Porwell 15

Here's a new piece: 99edo porwell 15.

This diagram shows the scale used by the piece. Green arrows are perfect fifths (3:2 frequency ratio), blue arrows are major thirds (5:4), and red arrows are the less conventional 7:4 interval. Tracing paths in the diagram, there is a direct connection, a perfect fifth, by which one can move from pitch class 32 to pitch class 90. One can also get from 32 to 90 by way of two red arrows and three blue arrows, e.g. moving through pitch classes 64, 96, 77, and 58. This convergence of paths is how 99edo tempers out the Porwell comma, 6144:6125.

This scale has 15 notes per octave, with spaces between notes of sizes 7, 6, 6, 7, 6, 7, 6, 6, 7, 6, 7, 6, 6, 7, and 9 steps of 99edo, i.e. quite evenly spaced.