The Roland HandSonic HPD-15 hand drum includes some tuned percussion instruments. You can edit the pitch of each pad in cents. The pads are grouped into 3 sets of 5, as shown:
You can edit the pitch of each pad individually, and further adjust the pitch of an entire set (A, B or C). The pad set adjustment is very helpful when creating a patch for any HPD-15 instrument that is voiced for a higher or lower octave.
After several experiments, I finally settled on this arrangement of the Bohlen-Pierce scale notes. It is fully chromatic from D to D’. I didn’t include a low Db as it seemed less important than the high D’ for modal music.
I tuned the notes to the C Lambda scale in just intonation with A=440 Hz (pad A2). The first song recorded with this system was Fuse Blue. The HPD-15 is somewhat buried in the final mix. I’ve created a separate MP3 file of just the HandSonic tracks so that you can hear what it sounds like:
I’m happy to answer any technical questions from other HandSonic players who are into BP or other alternate scales. The HPD-15 isn’t a real sensitive instrument, but its fine tuning capabilities make it a very useful tool for creating a variety of sounds in real time performance. I advise using a good frequency meter when tuning, as the readout of cents isn’t really very accurate. The tables below contain the fine tuning adjustments that I developed for several of the unit’s virtual instrument voices.