Recently in http://groups.yahoo.com/group/Rollscanners/ Phil Dayson brought up a slightly off topic thread about visual effects in mechanical instruments.  A main theme is how elements like the moving perforated roll adds to the impression of a mechanical instrument.

My own organ is pretty dumb to look at, being MIDI controlled.  Onlookers often tend to hold their hands above the pipes to find if they can feel the airflow from them.  Mostly they don't.  But at performances I have noted people were quite fascinated by the 'flags' I had installed for maintenance purposes on my accompaniment chest.

So now I have installed such flags everywhere in my organ; a close-up photo is attached of a few of those on the melody chest.  A 1.7 mm diameter 'bleed' hole is drilled from outside into each note channel.  Each hole is covered by a 5x28 mm strip of thin motor cloth, held at its top end between two washers by a screw.  Its bottom end is visually accentuated by a glued-on confetti from an office paper punch.  When a note is turned on its flap is deflected outward by a tiny jet of air from the note channel.

Apart from its maintenance utility I find this to be a good eye catcher, also illustrating that even in a 'rich' arrangement there are really quite few pipes simultaneously turned on at any one time.

Johan Liljencrants
Stockholm
Sun, 23 Jan 2005 13:08:23 -0800

Read the newspaper article, "The Professor's Remarkable Organ", at http://www.fonema.se/dnpastan/dncity.html