Colin Pykett

Apologies for the misunderstanding, Paul. Reading your post more carefully I can see what you were saying. And continuing with psycho-acoustical effects such as those hinted at by Stanley, apparently there is a condition in which the two ears perceive different pitches for the same note (I think it has a medical name but can't remember it - maybe Stanley knows). In one case the difference was reported to be about a semitone! Maybe this might help to explain why some people embrace atonal music with its dissonances more enthusiastically than others, if their ears and brains process sound differently to those who prefer tonal music? Or why some people genuinely might be 'tone deaf' and get little pleasure from music?

I don't think handsoff is hearing things. A pitch change when the intensity of a constant-frequency sound changes fairly rapidly is a well known phenomenon, though it is subjective and therefore an aural illusion. Like Paul, I experience a slight flattening effect though, rather than a sharpening. It's particularly noticeable (for me) when the last chord of Saint-Saens's organ symphony dies away into the reverberation on the Fremaux/CBSO recording with Christopher Robinson playing the organ (Classics for Pleasure 0946 3 82233 2 0). However I once demonstrated the effect to an otological university research specialist, who could not detect it at all, at least on that particular recording, though he was aware of the effect in general. It isn't an artefact caused by the reverberation as such as this only affects the sound intensity; it cannot change the frequencies involved, unless something is moving in the auditorium and thereby imposing a Doppler shift on the sound. People moving around can sometimes generate such frequency (in fact, phase) shifts which can be noticeable, though this would not usually happen at an actual concert until the sound had completely died away and the audience started to leave their seats. And on the CD referred to above there was no audience, though it's conceivable that someone such as an engineer was creeping around close to the microphones I suppose, or maybe a sound-absorbing curtain was wafting around in a draught from the air conditioning, though I'm clutching at straws now. However, and getting off-topic, this business of people creeping around can ruin attempts to record high quality sound samples from organ pipes - I've certainly come across that from time to time in some 40 years of trying to do it, and it's usually not until you come to replay them that you realise they've been corrupted in that way (and at that point it's difficult to resist the temptation to kick some ass ... ).

I should perhaps have mentioned this earlier, but Freeman Dyson, son of Sir George Dyson, died on 28 February. The earliest recollection I can recall of Sir George is that some of the piano pieces I laboured through as a small boy were from his pen. But since I later followed a career in science rather than music it is his son, Freeman, whose work I am more familiar with. It isn't for me to take readers through the achievements of either of them, but they were both more than notable in their respective fields. I wonder whether the unusually broad and sometimes controversial aspects of Freeman's scientific career might have been encouraged by his exposure to the Arts as a youngster - he was certainly one who took an interest in, and contributed to, a bigger picture than that which most physicists seem content to look at. What a gifted pair they were, covering such a wide intellectual spectrum between them.

Your post suggests that you know what the problem is but can't find a way to resolve it. Like you, I imagine that Zoom's default audio settings think that any quasi-continuous sound with a short-term constant crest factor (such as organs when playing relatively slow homophonic music such as hymns) is in fact background noise which therefore must be cancelled out. Other types of music (i.e. those most often encountered) have a more peaky crest factor (such as your piano, guitars, etc), are therefore correctly recognised as music, and therefore don't get cancelled. My hearing aids sometimes do exactly this unless I switch them to 'music' rather than their 'speech and everything else' mode. There is a setting in Zoom called 'Preserve Original Sound'. Not having tried it, I don't know whether this will solve the problem, but it can apparently be switched on and off. See: https://support.zoom.us/hc/en-us/articles/115003279466-Preserve-original-sound I hope you can solve the problem, but am pleased that at least you could use your piano if all else fails. In these trying and stressful times I do send my best wishes for a successful service, which will be of so much comfort to a lot of people, perhaps even more than would normally attend your church themselves.

Responding to Rowland's question, pipes have to be made to withstand, without their walls flexing, the high vibrational pressures which occur at the pressure antinodes along the standing wave which is set up within the enclosed air column. If there is even a tiny leak or if the pipe walls are not strong enough, especially at these points, the pipe might not speak at all as Damian mentioned, or it might do unexpected things. (When stopped wooden pipes sometimes go off speech it is often because the tightly-fitting stopper at the top has started to open the joints, sometimes before this can be detected by eye. Pipes simply will not work properly if there is any leakage). This explains why the holes used in harmonic flutes only need to be minute to get the pipe to speak an octave higher because the pressure at these points is so high (the hole allows the pressure at the fundamental frequency to leak away, therefore the pipe cannot form an antinode at this frequency, therefore the lowest frequency sounded by the pipe is the second harmonic - the octave - rather than the first harmonic - the fundamental). Pipes whose walls flex too much exhibit similar problems to those in which there are leaks in that the nodal pattern is degraded - this happened more often in the early days of organ building, when some centuries-old pipes with thin walls can be difficult to put back on speech. I should imagine that the best organ builders will know all this, either from hard experience if not from physics, so if they construct their pipes from several sections, perhaps they arrange the joints so they are likely to result in minimum disturbance to the internal pattern of standing waves. Having said that, the massive construction of a 32 foot pipe means that the odd joint or two here and there is probably unlikely to have much effect. It's an interesting question all the same Rowland. PS This is my take on the matter, also as a physicist(!), written before I saw Lausanne's above. However it might be nice to get an organ builder's view. John Mander contributed above; maybe he also has a view on this aspect as well?

I've mentioned this before but it might be worth repeating. The organ was built exactly at the time when a sudden expansion was occurring in the options available for making loud musical noises in large buildings. Prior to that, the only way to achieve it had been to build a pipe organ, and that was one of the reasons it was invented centuries earlier. But in the 1920s electronic valve amplifiers started to appear, partly capitalising on the accelerated developments during the first world war. The first commercially practical moving coil loudspeaker also appeared at this time. However both the amplifiers and speakers were inadequate at first to fill a space the size of the Hall with sound of the necessary power and of passable quality. Also some other essential components of a half-decent audio system (microphones and electrically-recorded gramophone/phonograph records) were likewise still in their infancy. So, at the time, it was likely that a pipe organ was still deemed to be the best solution for providing a musical background to events in the Hall, or for providing music in its own right at concerts. Also the Great Depression reduced the manufacturing capability of some electronics companies and wiped others out completely, thereby reducing the opportunity to shop around for a music system of the necessary capabilities for such a huge space. Thus the organ was installed in the Hall instead. It is possible that those who considered it unmusical were always in a minority, because its main purpose of making a loud and impressive noise had been achieved. However, within a few years the shortcomings of early audio systems had been largely solved, plus the fact that electronic organs such as the Hammond (and, not much later, many other makes such as those by Baldwin) were coming along as well. So unfortunately the pipe organ would probably have been seen fairly rapidly as a white elephant by the Hall's management, with a corresponding lack of enthusiasm to keep it properly maintained and fit for purpose at a time when cheaper options for doing the same job were emerging rapidly. The situation is analogous in some ways to what happened to the theatre organ, which also was eclipsed by the same rapid developments in audio electronics which, in that case, led to the talkies.

I've pondered for many years about Compton's demise, and Tony might well be right. When the Electrone first appeared it offered the church organist an identical physical playing experience to the pipe organ, rather than requiring them to adapt to the new console arrangements of the contemporary Hammond. Yet both were not dissimilar in the range of sounds they could produce in that they both used additive synthesis using only a small number of harmonics, a disadvantage forced on them because of the technology limitations of the day. Hence the Electrone became more popular in the UK for the 'classical' organ market because an organist could get onto the bench and play it straight away rather than having to mess around with unfamiliar things like the Hammond drawbars. But as time moved on I don't think Compton's saw the potential for the fully electronic (rather than electromechanical) analogue organ which was being rapidly developed in other countries, especially the USA. Thus some of the early, larger, custom analogue Allen organs (which used many valves performing subtractive rather than additive synthesis) were producing very fine sounds by the 1950s and 60s, far better than those of the Electrone which in my opinion sounded cloying and muddy in comparison, and they too had the advantage of standard console arrangements as did the Electrone. As time moved on further Compton's were therefore getting left behind in terms of tonal quality, as well as not being able to capitalise on the increasing cheapness of electronics compared with their increasingly old fashioned expensively-engineered rotating disc generators and their horrendously elaborate hand-wired signal mixing (voicing) methods. All this might have been because they did not seem to bring in enough of the right sort of expertise for some reason. When Leslie Bourn retired (one of the prime movers behind the Electrone system) he still had no familiarity with transistors, which virtually every other electronic organ manufacturer world wide was by then using by the shed load. I can say this with certainty and without wishing to denigrate his capabilities because he himself wrote in a magazine article that "it was about time I started to find out about these little transistor thingies". So by the second half of the 20th century Compton's were falling behind technically, and thus in tonal realism, even while their organs remained comparatively expensive. So presumably people stopped buying them, thereby contributing to the failure of the firm. At the same time the cash cow of the cinema pipe organ market had long collapsed. In the late 1960s I visited their factory and played a 4 manual Electrone, which was by then the sole occupant of that vast floor space which once was a thriving hub of activity. It was an extremely sad experience. And I'm afraid I wasn't even particularly enamoured with its sound, although the console of course remained sumptuous and splendid (and expensive). It seemed to me to be an epitome of the lose-lose-lose situation (expensive electronic organs/old fashioned technology/shrinking pipe organ business) which led to their downfall, which in my humble opinion was the outcome of poor business decisions over an extended period as much as anything else. They seemed to just carry on doing what they had always done in the electronic organ game for far too long, without looking out of the window to see where everybody else was going. Quite why this was allowed to happen still mystifies me though. However it's easy to be wise with hindsight. Although the above relates mainly to electronic organs I hope it will be acceptable on this forum in that it also relates to the history of a celebrated pipe organ builder.

The Zoom H1 is also worth considering if you will only be doing occasional recordings, or if you just want to explore what digital recorders can do. It's the baby of their range and incredible value for money. I was given one by a kind friend and was astonished when I started to explore its functionality. However I found it was worth getting the H1 accessory pack (not expensive) which also includes a small telescopic tripod to mount it on. That's really handy, and as the tripod has a standard camera mounting screw, I sometimes use it for taking close range photos with a high quality camera as well when a phone isn't good enough.

Robert Hope-Jones incorporated sforzando pedals in many of his organs from his very first one at St John's Birkenhead (c. 1890). This had two - one brought on the heavy reeds (Tuba, Clarion and Ophicleide on 250 mm wg) and the other brought on full swell plus couplers to great and choir, and it also threw open the swell shutters. They looked like the ordinary projecting iron combination pedals of the day. Would such devices have actually been musically useful, for instance in works such as Elgar's Organ Sonata, or were they just gimmicks? The Birkenhead organ also had a novel type of swell pedal. At first sight it appeared to be just an ordinary balanced type of swell shoe, but it had two modes of operation. The system is best described by H-J himself, taken from the lecture he gave in 1891 to the College of Organists (the forerunner of the RCO): "The swell pedal, which I prefer to make self-closing, is returned to its position by a spiral spring only, so that its movement is not in any way impeded by the inertia of the swell shutters and connecting mechanism. On this account it responds more readily to the organist's wishes. By the employment of varying electrical resistances there is no difficulty in securing simultaneous and synchronous movement of the pedal and the shutters, and this may readily be managed through a single wire. [It was in fact an early type of servo-mechanism - CEP]. The swell pedal, though self-closing, will remain in any position if the slightest pressure tending to move it towards the left be exerted. A touch in the opposite direction will liberate and allow it to close. The pedal cannot remain in a middle position, but will spring either right or left. Its sideway [sic] movement is very slight. A stop-key may be provided, with those governing the registers on the swell organ, which will open the swell box without the necessity of touching the pedal. Such a stop-key must however be automatically thrown out of action as soon as the foot touches the pedal. In this manner the swell shutters are always amenable to the pedal, though it is possible for the organist, when sweeping his finger along to bring out full swell , to open the box also, should he desire to do so". [The Birkenhead organ had such a stop key - CEP]

Scrolling three posts above brings Stanley M's post into view, which began on-topic but then moved onto the fragility of the tradition of church music itself. He makes some powerful points, informed by his knowledge as an insider both of the church (a recently retired priest) and its music (he has the warpaint - FRCO etc). It chimes with me, perhaps because I do not have anything like that depth of professional experience of either field and therefore cannot gainsay it, but also because I have made my views known on this forum about what the future of the pipe organ might be simply by looking at the future market for it in a business sense. Both Stanley's views and mine are independent but they are similarly negative, if not depressing. Reflecting on this, two questions are in my mind which I cannot answer. Are those such as myself who hold these views misguided, and if so, where are the more positive alternative world views to be found? And secondly, what sort of person would take up a career in church music today? If the negative view cannot be dispelled, what career will there possibly be over a typical span of 40 years, say? Are the only candidates the few who have independent means? Otherwise, aren't they taking the most appalling gamble in choosing the profession? This latter aspect is potentially very sad, given the years of academic slog that a typical cathedral appointee in her mid-20s has already had to go through to get there. When I ask questions like this I get stuck.

I just noticed that the item is still in my 'watch' list (because I put it there the other day) even though it's now stated to be 'out of stock'. It was listed under the heading 'COMPTON ORGANS, A STORY OF ORGAN-BUILDING GENIUS'. So you could maybe set a search watch (or whatever the correct title is) for this term, or just use COMPTON ORGAN perhaps. Then you'll get emails every time an item with those words in the heading appears. You might also get miscellaneous stuff related to pipework, consoles, tremulants, relays and lord knows what else, but it should also trap the disc you want. Update: I just searched for 'organ', then organised the results by 'newly listed'. Lo and behold, the first two items which appeared are the very ones you are looking for. One of them has the ebay item number 143518777694. So if you're quick you might just get it ... (Good luck!).

Oh dear Paul, I'm sorry if my opinion caused offence, especially if you are currently a BIOS member yourself. Yes, of course anyone can join BIOS, and I have been in the fold on two occasions going back to the 1980s when its illustrious founder-members were still running the show. And when you are a member then, naturally, you get the regular publications automatically. But for something of the magnitude of MusoMusing's work, that would probably have been published separately if it had hypothetically been done through BIOS, and they sometimes do this as you will know. But I have experienced difficulty on several occasions when trying to order these types of one-off publication, both as a member and non-member (which I'm presumably entitled to do since they were advertised on the BIOS website when I last looked). The difficulties have been considerable, such as not getting replies to emails to the publishers of the items in question seeking basic info such as how to pay for them (because the publisher's web site did not offer that facility, or subsequently seemed to have shut down completely). So that has been my experience for what it's worth. And as for 'closed society', the term was perhaps ill-chosen, but I find it 'closed' in the sense that it's difficult for the community outside the membership to get much information about the said publications, though again it's quite possible things are different now. Added to the other problems, my view is that 'closed' is a fair description of my own experiences. I can't speak for anyone else of course. What I can say is that I spend a lot of time discussing and corresponding within the global 'organ' academic community, and find that BIOS does not seem to be particularly well known outside these shores. On one occasion there was, in retrospect, a hilarious exchange with a US academic who thought I was referring to the BIOS on computer motherboards! So I'm afraid its visibility might not be quite as good as its work merits, but again, perhaps 'closed' was the wrong adjective. I hope this answers your question as to 'what I meant' by the remarks in my post, and I'm also pleased that you agree that it's my business whether I choose to be in membership or not, though I'm grateful to have been reminded of the fact. (It's curious that you broadcast a presumption about my membership status though. Aren't such things private within BIOS nowadays?). But this thread is not about BIOS, it's about MusoMusing's magnum opus on Compton, and I reiterate my pleasure that he's made it so widely available and so cheaply. I hope you find it as rewarding a read as I have done.

Many congratulations. I'm so pleased you've released the fruits of your labours to the wide world, rather than issuing it within a closed scholarly society such as BIOS as some other authors do. That's all very well, but their global membership is so small especially in the context of today's internet era (c. 600 - 700 when I last looked), and getting hold of the publications is difficult for those outside the fold and far more expensive than what you are asking. My experience of doing similar things over the last 20 years or so is that, yes, you have to put in a lot of effort and, yes, it does cost a fair amount of money. But I think you will now come across the upside in that you'll probably get a lot of very appreciative correspondence over the months or years to come which (in my case anyway) more than compensates for the hard labour!

Yes, varying buffer size is the next thing to try. Audacity, as well as the computer in general, both have to do lots of other things while trying to replay each audio sample at exactly the right time, such as updating the pretty graph display on the monitor. Even more intensive are things like reverb (which you mentioned). So you could also try switching off the reverb and see if the clicks go away. Also try switching off any other audio effects you might be using, such as EQ (tone control), externalisation (enhanced 3D effects), etc.

Sorry to keep banging on about it, but if one wants or needs to retain recorded information for an indefinitely long time, then the problem of 'media rot' is a major one as I said in a post above. Hence my interest in keeping backups, not only as backups per se, but backups on different types of physical media. This is where things like minidiscs come in because, as John Robinson said, they might not be the tops in terms of the latest hi-fi, but they are one more useful weapon in the armoury. It's better to have something than nothing at all if the worst happens. A current example today, as it has been for 20 years or so now, is vital data recorded on early 8 inch or 5.25 inch floppy discs. Where does one get the drives and the old computers from to even see whether the discs are readable any longer? And are they in good enough condition not to wreck the disc when you try to read it? Etc, etc. This is one reason why banks keep having IT crashes because the core of some of their systems are ancient 1980s computers like DEC VAX's with data stored on equally ancient media such as these types of floppy, DEC tape, etc. I'm perhaps going off topic a bit as far as organ recordings are concerned, though even here some recordings might become of great interest and value decades into the future, so one can't entirely ignore the issue. HOSA (the Historic Organs Sound Archive project) is an example.

Agree entirely! It's a pity in my view that the Minidisc came and went so quickly, but the main reason was that there wasn't enough pre-recorded material made available quickly enough to satisfy the largely teenage market, and simultaneously the sub-market consisting of those (like you and me!) who wanted a new, economical and convenient way of making digital recordings just wasn't big enough. However there are signs of an upturn in interest, though obviously only for the existing equipment still around which seems to be getting quite sought-after now. As an example, I bought a Sharp portable (Walkman-type) player/recorder nearly 20 years ago when they came out at a cost approaching £100. Lovely little thing, and still working fine and very handy to have. In 2010 I got a nearly-unused identical model off ebay for less than £10 as a back up. But now the same items are attracting almost their original prices again. So there must be a small army of people out there somewhere who share our views!

You've obviously come a long way up the learning curve in a short time - congratulations if I may say so! One reason for clicky recordings is that the PC you upload to isn't fast enough to cope with the data stream from the Tascam. What sample rate did you use on the Tascam when making the initial recording - 96 kHz perhaps, or even higher? If this is the case, maybe try making a new recording at 44.1 kHz on the Tascam and see if the click problem has disappeared when uploaded and replayed in Audacity. If so, then try using Audacity to reduce the sample rate of one of your existing clicky recordings and observe whether the clicks then disappear. This link might also help - https://forum.audacityteam.org/viewtopic.php?t=92782 There's a lot more out there on the subject, but much of it isn't relevant because one of Audacity's features is that it can remove clicks already on the original recording which might have come from a vinyl original for example, which isn't the same thing of course.

Splendid stuff! It reminds me of something I can now only barely recall (to the extent I might be deluding myself) - that the 'march' theme in the Dambusters 'goes' with that of Eric Coates's other work 'Calling All Workers'. This was the signature tune of a daily 1950s/60s BBC radio programme called 'Music While You Work' that I remember from my childhood. Much later, though still a long while ago, I think this congruence was demonstrated when an orchestra played an arrangement of both being played simultaneously. This might have been a 'Friday Night is Music Night' programme as part of a tribute to Coates. I wonder if anyone else can recall this? The 'Calling All Workers' theme is below. I'm sure Messrs Gledhill and Hills would be more than up to the task of demonstrating it on a theatre organ, given their performance above. https://www.youtube.com/watch?v=RhtOWG8aPC0

Actually Paul, looking back over this, I didn't really answer your question properly - apologies. If we go back to Contrabombarde's original question: I assumed (without thinking about it too much) that he was talking about rain - liquid water rather than vapour. So I assumed this would increase the density of a given volume of the atmosphere. However if I'm honest I don't really have much of a handle on what this might do to sound passing through it as there are too many variables (precipitation rate, etc). And in any case we wouldn't actually have rain in the auditorium housing the organ even it was raining outside - unless the roof leaked badly. But the presence of rain would also saturate the air with vapour, probably inside the building as well as outside, which brings us back to where we came in. Re your further point about Figure 2 in your link, it illustrates the anomalous variation of absorption for damp as opposed to dry air. Though on first sight these (theoretical?) curves don't seem to correlate too well with the experimental data of Evans & Bazley I mentioned earlier. But we've probably gone way beyond what Stanley Monkhouse had in mind when he set us this disarmingly simple exam question in the first place ... so I think I'll draw stumps for now.

I thought this might come up! I've had to explain it often in the past. There are three issues: 1. Absolute humidity is not the same as relative humidity (RH). RH is the amount of water vapour present in air expressed as a percentage of the amount needed for saturation at the same temperature. Assume we have a volume of air with a given mass of water vapour in it i.e. the absolute humidity is constant. Now vary the temperature. At low temperatures the RH becomes higher than at high temperatures because at low temperatures the air saturates more easily, even though the amount of water (absolute humidity) remains the same. Put another way, the same amount of vapour gives higher RH in cool air than warm air. 2. Sound attenuation at a given frequency (e.g. measured as dB per metre) gets higher for low RH (warm air) and lower for high RH (cool air). Lots of references here going back to the year dot - e.g. Evans & Bazley 1956. So there is less attenuation if the temperature drops. 3. Attenuation at a given RH gets lower as frequency gets lower and vice versa. Upshot: Attenuation is low for conditions of high RH and low frequency, and high for low RH and high frequency. Therefore as I said previously, one gets more treble (high frequencies) if the RH is high, which for constant absolute humidity, means at low temperatures. Thus music sounds more brilliant in the cold, as Stanley and the recording industry have observed. I haven't looked in detail at the links you gave as unfortunately some of those I have looked at in the past have got it wrong. Some of what's in Wikipedia is also wrong. I think the main problem is the counter-intuitive relation between absolute and relative humidity and their variations with temperature.

As I said in my last, we're actually on the same page of the hymn book. I see exactly what you are saying, though remain unconvinced that I've explained myself adequately in return, for which I apologise. But I'm not sure there's much to be gained by pursuing it any further, at least from my point of view. I think I'll spare the forum any more grief!

I think you might have missed the points I was making. These points are all objective, not subjective, and based on nothing more than arithmetic. What I was trying to point out (quite probably inadequately) is that, in terms of the practicalities of tuning, there isn't much difference of principle between the temperaments. In both meantone and ET one tunes 11 fifths so that the frequency ratios of their constituent notes are the same. The actual ratio used depends on the temperament you are tuning, the values in terms of commas being those mentioned in my earlier post. The arithmetic then means that the remaining fifth (the 12th fifth which completes the circle and doesn't need to be tuned) automatically becomes a Wolf in meantone, whereas it automatically stays the same as the other 11 in ET, i.e. all 12 have the same inoffensive ratio with no Wolf. What I then went on to say was that if you play in the restricted set of 'good' keys of meantone you are not using the Wolf interval. You are only playing on the notes which constitute the 11 other fifths. If you were to use keys which included the Wolf you would not get as many of the lovely thirds, but dissonances instead which some people regard as hideous. Because the 11 non-Wolf fifths whose notes constitute the 'good' keys, all having the same interval ratio, they form one of the class of equal temperaments. Because it is equal there is no discernible key colour between these 'good' keys. However, to say otherwise is understandable because it is a widely held misconception, but it is nevertheless a misconception. Only when you stray beyond the good keys into those which call on the Wolf interval do you get a sudden change in key colour - indeed the injection of 'sourness' as you put it. I know that it can be difficult to get one's head around this, but please bear in mind that it's not just little old me who makes these points. In the mid-1980s the late Charles Padgham in his well known treatise ('The Well-Tempered Organ') said of quarter-comma meantone: "It is sometimes forgotten that mean tone temperament is a form of equal temperament except for one fifth, the Wolf. All the other fifths have identical tempering. Thus the 'good' keys are identical except for pitch, and true 'key flavour' does not exist among these good keys as it does in the irregular temperaments." And for sixth (Pythagorean) comma mean tone - the so-called 'Silbermann' temperament - he said again: "There is also no different key flavour amongst the good keys". In more recent times Fred Sturm is just one well known writer and professional piano technician (a name which scarcely does him justice I might add) who has made the same points, and (as I have done here) he has also drawn attention to the widespread misunderstandings which have resulted in many people holding the view that the meantone temperaments possess a wider range of key colours than they actually do. Oh, and while we are at it, let's dispose of another myth. It is often claimed that ET was slow to catch on because it is difficult to tune. That's true - one has to carefully temper 11 fifths. But all the meantone temperaments also require that 11 fifths are carefully tempered, so they are just as difficult to tune as ET. The one exception is that quarter-comma meantone has several pure major thirds and minor sixths which can be used along the way to check that your fifths are accurately tempered. I maintain that's one reason why quarter-comma might have lasted for as long as it did. (All this, of course, refers to the ancient methods for tuning by ear and without timing beats, not using electronic tuning devices). Having said all this, I am completely with you in trying to persuade people to explore the beauties of unequal temperaments. In this aspect we sing from the same hymn sheet. But at the same time one has to be a bit careful that we do not help to propagate long-held and widely-held misconceptions such as these, which unfortunately are demonstrably wrong.

Well, I did used to work in sonar ...

The issue is to keep humidity as low as reasonable, and if air conditioning incorporating full climate control is available it can be adjusted. But to answer your question, a dry day ought to be better, since it's the increased density and higher thermal conductivity of high-humidity air which both conspire to kill the high frequencies more than the low ones. I doubt there would be much difference noticeable due to the humidity effect in small rooms though. It's only where the path from the pipes to one's ears is long enough such that the differences in attenuation with frequency become significant. In a large building with a long reverberation time (several seconds) the multiply-reflected path lengths contributing to the later parts of the reverb tail would correspond to thousands of feet since the speed of sound is about 1100 ft/sec, and over these distances the effects we are talking about here would definitely become noticeable. A 5 second reverb implies path lengths due to the multiple bounces approaching a mile or more! Clearly these could only exist in large buildings such as cathedrals, and it is in these where the effects described by Stanley in his original post can be noticeable. It begs the question of whether performers ought to put a rider into their recital flyers along the lines of "weather permitting". Then they could cancel it if the temperature and humidity turned out to be out-of-spec. (No, not really ... ). However I'll make a note in my diary to serve this up again on 1st April to see if forum members have forgotten about this thread in the interim.

As you would be reproducing the organ part on an instrument which can be controlled via MIDI, I suppose you could just let the organ 'do its own thing' while you yourself play along with it on the piano. The organ would quite happily be able to read its own score regardless of technical difficulty if you have it in a Sibelius, Musescore, etc type of format. However I do have tongue firmly in cheek when suggesting this, as I realise it would completely remove you, as a professional musician, from making virtually any stylistic input to the organ side of the performance! In the worst case it would just tick along at an invariant, mechanical and thoroughly unmusical pace. Having said that, there would be ways to ameliorate it as you no doubt know, such as using the 'click track' method whereby you first generate an acceptable MIDI performance on the organ including things like rubato, etc (thus also including a tempo map along with the clicks), with the resulting recorded MIDI stream then played back as 'clicks' into headphones which you wear while you subsequently add the piano part to the mix. It's a standard technique used by recording studios for laying down both pop and classical multitrack mixes, which is one reason why everybody (including the conductor) is often seen wearing cans in studio recording sessions. I realise that your musical freedoms could be heavily constrained if you go this route, but on the other hand, I wonder how many of those who subsequently listen to the final recorded product would realise how it was achieved? It could sound pretty convincing nonetheless, just as so many studio-generated recordings do. I'm not really adding much to what you suggested in your original post, except to suggest that the organ could play an 'impossibly difficult' score if you provided it with the appropriate MIDI input format.