Spenta Mainyu – Jack Walrath

Spenta Mainyu was originally recorded in a piano-less, two-horn quartet setting; this song is a good example of the open-ended sound that such a lineup often has. It's a modal song, based on a simple bass vamp that repeats an open fifth. The mode itself is not so obvious: a unique symmetrical scale, including two pairs of half steps with two augmented seconds in between. The scale is shown at the beginning of our score and all parts. The underlying bass vamp shifts from E♭ to G; the E♭m(maj7) and Gm(maj7) chord qualities are both within the scale. In its slippery winding lines, the melody implies both chords while staying linear in the mode. Some of the other chords in this song are inversions with open fifths in the bass such as G♭maj7/B♭op5 (again all from notes within the mode).

The form for both head and solos is ABABCD. A and B are both eight measures long, staying on the mode; C (also eight measures) is a sort of bridge that goes to a C minor key center, with a two-measure break at the end. D is a truncated four-measure version of A with rhythm section hits at the end. The break and hits are played in the solo choruses (indicated "always as written"); after the first chorus of each solo, the bass walks except in these places. There is a chorus of harmonized horn hits for the bass solo; this is followed by a drum solo over the bass vamp. The vamp returns as a coda, with the horns improvising together; the end cue is a two-measure figure based on the beginning of B.