Buffalo Panic

This ambient piece was performed using 4 Bohlen-Pierce instrument patches on the Roland HandSonic, with guitar effect boxes.

the home recording setup for this piece

It was recorded as 4 stereo tracks on the Zoom R8, then finalized in Audacity on an iMac.

Tajamby, steel guitar improvisation

This ambient piece employs 3 steel guitar parts: a bass+drone, a two-note baritone figure, and a melody line. The accompaniment is a tabla drum loop and road noise. The video was created with Magic editor.

Bohlen-Pierce fretboard by Andy DePaule

Tripolar Expedition

This algorithmic piece picks random notes from the Bohlen-Pierce scale for a soothing ambient effect. There are 17 iterations, each dropping the highest note from the remaining list.

Tripolar Expedition

Stacking 3rds

This short piece, titled “Providence”, contains overlapping Bohlen Pierce chords. Each note includes a harmony 439 cents (9/7) above and another 439 cents below. A pleasant effect with no real parallel in the 12-tone system.

Melodyne 5 Editor

These two pieces were retuned to Bohlen=Pierce with the Melodyne 5 Editor. The first is a jazz piece I wrote on guitar as a teenager, reimagined in Band-in-a-Box with a trombone as the lead instrument. I wonder if an actual trombonist could play these notes.

Trombone Jazz

The second is a sound collage based on Dennis C. Lee’s “Psi-seX 1”. Running these somewhat random noises through a musical scale filter makes a rather pleasant effect, in my opinion.

Testing PSA

Adapting a Keyboard

Here’s one way to adapt a standard 12-tone keyboard to play Bohlen-Pierce music. Some of the black keys are not used because the BP scale has fewer accidentals. The actual pitch reassignments must be done in software somehow.

8 String Lap Steel


I usually tune my steel guitars to D6 with G bass (G B D F# A B D F#). The Bohlen-Pierce tuning below uses the same string gauges with a BP fretboard designed by Andy DePaule.  I simply place the fretboard over the standard one and retune to play in BP.

If you use a Peterson Strobe HD tuner, you can install the BP tuning table from the “Uncategorized” list at petersontuners.com/sweeteners/shared.  That’s a lot easier than eyeballing the cents numbers on a traditional electronic tuner.

BP note 12 EDO Tuning
H F -39
G Eb +14
F C +22
Db Ab -17
C Gb +37
A D -2
H Bb -41
F F +20



Here’s some ambient music played on it:

“Blessed Peace”

Not In C

This Bohlen-Pierce arrangement of Terry Riley’s “In C” was realized on the musical hardware described in Rehearsal Room. It was performed by 13 identical algorithmic musicians known collectively as The Technical Academy. A characteristic feature of the ensemble is an indiscriminate fader controlled by a Markov chain on each voice. This is the third recording of the completed algorithm.


The notes of Terry Riley’s original score were remapped to Bohlen-Pierce notes in a slightly modified A Moll I mode; the B note would have mapped to BP’s J, but it was changed to Jb simply because Jb sounded better.  Riley’s C D E F F# G A Bb B becomes A B C D E F G H Jb. The work is titled “Not In C” because it’s based on this different scale.

In Odd tone map

Source code written in Ruby can be viewed at github.com/b0blee/TechAcademy.

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