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contrabordun

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Posts posted by contrabordun

  1. In a sense, that's just as big a liberty as changing the notes, because it directly contradicts what was printed on the page

    I think you're being too hard on yourself here. After all, whatever the label on the stop knob, Franck never had the H'n'H sound in mind when he wrote it, but he did think of those notes.

     

    Mendelssohn was quite explicit about this in his preface to his Sonatas, saying that he had given only dynamic markings because stops of the same name sound different on different organs. (And, he might have added, in different acoustics).

     

    We are lucky enough to be able to travel, or at the very least to be able to hear good recordings of the instruments for which pieces x, y and z were written. We know what sound the composer wrote for. If we don't have that sound available we have to make an artistic judgement about which of the available resources best conveys what was intended.

  2. a large 3 phase, four stage Discus from a church...for a couple of seconds it drew over 100 amps

    ...ok... a 3 phase motor uses about 70% as much current for a given power rating as does a 1 phase (on which my earlier calculations were based, Theophilus), so 100A 3 phase @ 240V equates to about 36kW, which would cost £3.60 to run for an hour, or 0.2p for the couple of seconds....

  3. Technically, he's accessing this fascinating exchange via his school intranet which provides him with access to the public internet on which the Board is situated. The bottleneck could be either on the intra- or the inter- net, and is quite likely to be the former.

  4. oh goody you've hit on one of my pet hates...in my case it was 1988 and £1 an hour, and I still thought that extortionate. You'd have to play a lot before you started adding to the wear and tear on the instrument*, so the practice fees are pure profit to the Church, and fall upon those who can least afford them. If you're a normal suburban teenager the practical barriers (transport, time, keys, delights of wading through p****d up locals on your way out in the dark) to doing the sort of amounts of practice that most musicians would take for granted are bad enough, without being charged for the privilege.

     

     

     

    *correct me if I'm wrong, but I've heard it said several times that organs last longer and in better condition if played more than for a few hymns every Sunday

  5. At most, something like 15p an hour. Quite probably half that. If you want to know more precisely, you'll need 2 pieces of information.

     

    1. The price your church is paying per unit (kWh) of electricity.

    2. The electrical power of the blower in kW.

     

    Electricity is somewhere around 10p a unit. If so, then a 1kW (1000W) blower would cost 10p per hour to run.

     

    The exact power your blower uses is probably probably printed (or stamped) onto a metal plate fixed to the far side of the blower and long since hidden by a thick layer of dust. If you find it, it might only give a figure in Amps, in which case the conversion figure is 250W for each Amp.

     

    If it says 3 phase supply...PM me...

  6. Depreciation I do not include because the value of the asset and its depreciation are assessed as part of the value of the

    business.

    No, you're wrong there - you should include the depreciation in calculating the running costs of the vehicle for this type of exercise. This is why the IR allow you 40p/mile (at least for the first 10,000 miles) and, as you point out, the marginal running costs are only a fraction of that.

  7. What this has to do with music publishing I've no idea!

    Dunno, I'm getting confused. I think that a Mr Crowther runs a mail order music shop from half way up the tower of Durham cathedral.

  8. I guess some people just live in a world quite removed from that of most

    It's easily enough done. 30 of my 37 years - including the last 12 - have been lived in houses without TV. As a result I have very little idea of what anybody famous looks like. I could walk through a room containing the entire English football and cricket teams, the British Cabinet and Shadow Cabinet (Blair, Brown, Cameron and Hague excepted), every current TV 'personality' (a few newsreaders and journalists excepted) and the casts of almost every Hollywood blockbuster released in the last decade and not recognise a single face. And strangely, I don't think I'm missing very much.

  9. although the metal will still expand and contract with fluctuations in temperature

    It's not the expansion of the metal - for a typical metal this is rather small over 25 degrees temp change - that makes the pitch change, but the change in the speed of sound in cold/hot air and the fact that this affects reeds and flues in different ways.

     

    NERD ALERT

    The speed of sound in air is proportional to the square root of the absolute (Kelvin) temperature of the air. In round numbers, the temperature inside a church will be 275K on cold winters day and 300K in summer, so the speed of sound in winter will be sqrt(275/300) x the speed in summer - about 0.95 x the speed.

     

    So in winter, sound travels roughly 5% slower. I can sympathise with that, especially when it comes to getting out of bed on a cold winter morning.

     

    The speed of a sound wave = frequency x wavelength, and it is frequency which the ear hears as the pitch of the note.

     

    For a flue pipe, the wavelength is set by the length of the pipe, which is fixed. So, if the speed of sound drops 5% from summer to winter, so must the frequency, so A=440Hz becomes A=418, almost a whole semitone lower.

     

    However, for a reed pipe, the frequency is fixed by tuning spring and doesn't change. The drop in speed of sound is compensated for by a drop in wavelength (the position of the antinode at the top of the resonator will move slightly). Hence the reeds stay true and the flues go flat in winter.

     

    If the dominant effect were the contraction of the metal from summer to winter, then the pipes would be shorter - and the flues sharper - in winter. Also, the reeds and metal flues would stay in tune with each other and the wooden pipes would be out.

  10. This organ looks familiar
    Does sound rather like the one I heard Paul Carr playing the Dupré B major on last summer. Unfortunately I couldn't stay for all of it because there was this girl next to me dressed in white who wanted me to come outside and have my picture taken.
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