Robbie mentions that Vicki Webb showed a pipe that responds well over
a wide pressure range.  This reminds me of some "well known facts" that
I had learned a million times in becoming a pipe organ lover, and which
I quickly UN-learned after I got hold of a 20-note Deleika crank organ
and later a 31-note Raffin.

Well-known "facts":

  "(1) Organ pipes (as opposed to free reeds as in accordions) are
   voiced for exactly one pressure, and will blow sharp or flat or
   overblow the harmonic or just hiss at you, if you raise or lower
   that pressure by more than a few percent."

But my Raffin has an internal handle you can use to press down on the
reservoir bellows top to raise the pressure, or pull up to lower it.
I can "goose"* a good accent or quick crescendo with this, and the
pipes barely go out of tune while playing noticeably louder.  And when
I put too many stops on at once, the pipes rob each others' wind and
play softer, but do not go flat (whew!).

  "(2) Organ pipes voiced on high pressure (such as used in monkey and
   street organs) must sound dull, thick, and tubby, while also strained
   and forced."

In reality, the Bourdons on both my organs sound more clear and alive
than any of their dull relatives living in church or concert organs on
lower pressures.  Their sound is not forced, but more as if they're
cheerful to be playing.

  "(3) High pressure pipe work must be 'nicked' to the point of no
   'chiff' or articulation."

Fact: Both my organs' pipes (except for the Violins in the Raffin)
chiff like a neo-Baroque tracker organ, or like a calliope.  Come to
think of it, nothing uses higher pressure than a calliope, and they
chiff like a xylophone.  To be fair, our organs tend to use the slider
windchest as advocated by Baroque enthusiasts.

  "(4) High pressure pipes must have arched upper lips, to avoid
   overblowing.  This makes for the expected dull tone."

All the pipes in both my organs have straight upper lips -- which may
explain their lively, unforced tones.

Anyway, so much for some eternal truths of organ building.  Could it be
that makers of street, monkey, and fair organs learned a lot more about
pipe voicing in the past 100 years than their churchly counterparts?
After all, look who invented the harmonic frein.

And a warning to those of us looking to scrounge old church organ pipes
for building our own street organs:

  Watch out, those old church organ pipes may not be good enough !

Mike Knudsen

 [ * Mike Schwimmer says the Yiddish word is "ootz" or "utz".
 [ "Give it a gentle utz" every now and then!  ;)  -- Robbie