Roland VR-700 important safety instructions What is footage?, Tonewheel organ’s overtone structure

Creating Organ Sounds

What is footage?

This comes from the length of pipes in a pipe organ. On a pipe organ, the pipes that sound the fundamental pitch of each key are considered by convention to have a length of eight feet (8’). A pipe that is half this length will produce a pitch that is one octave higher, and a pipe that is double this length will produce a pitch that is one octave lower. Thus, the sixteen-foot (16’) pipe is one octave lower, and the four-foot (4’) pipe is one octave higher.

A tonewheel organ’s overtone structure

In certain regions of a tonewheel organ’s keyboard, the overtones will not correspond to the configuration of the harmonic bars. In order to prevent unpleasantly high or low pitches, the high footage is “folded back down” in one- octave units for the high range, while the low footage is “folded back up” in one-octave units for the low range. The VR-700 faithfully reproduces this characteristic of tonewheel organs.

How the harmonic bars are arranged

If you take a look at how the harmonic bars are arranged, you’ll notice that the 5-1/3’ footage alone is not located in the order of its pitch. This is because the 5-1/3’ pitch is not a multiple of the 8’ pitch, but a multiple (the third harmonic) of the 16’ pitch. In general, sounds consisting only of overtones that are integer multiples will sound consonant, while sounds that contain non-integer multiples will sound muddy. Since the 5-1/3’ pitch is more easily understood as an overtone of a 16’ fundamental, the 5-1/3’ harmonic bar is placed beside the 16’ harmonic bar.

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