Daniel Stephen Johnson
December 16, 2013

"Möbius Loop" is an apt enough title for composer Mathew Rosenblum's new record from the Boston Modern Orchestra Project (BMOP). Like that topological construct, the album's titular concerto for the Raschèr Saxophone Quartet, presented here in versions with and without orchestral accompaniment, is both a mind-bending illusion and an elegant feat of mathematics – and so, for that matter, is every other composition on this disc.

BMOP's BMOP/sound label is never stingy with the liner notes, so listeners eager to learn how the music is put together will find mention of Rosenblum's customary 21-note-per-octave microtonal scale, combining the 12 notes of the piano with more unorthodox intervals that would fall somewhere between the keys, and the "19 note-to-the-octave 'equal beating minor third' tuning" the composer says he invented for Sharpshooter. The notes are written in the readable prose of the composer and of the critic Andrew Druckenbrod.

But listeners who don't care can throw the booklet over their shoulders and press play. One need hardly understand the math that goes into making Rosenblum's music in order to enjoy the result. It's interesting to know how his harmonies are constructed, but more exciting still are the surreal geometries that they conjure: straight lines seem to curve; smooth planes warp like, yes, Möbius loops, or Escher architecture. Or like the cartoon landscapes evoked by the splashy Double Concerto for Kenneth Coon, on baritone sax, and percussionist Lisa Pegher. This must be terrifically difficult music to pull off, thanks to its peculiar demands on the players' intonation, but BMOP, conductor Gil Rose, and soloists render these pieces with a steady hand.

These are all dazzling pieces of music, and while much of that dazzle comes from the strange iridescence of their microtonal texture, that microtonality is just one well-balanced ingredient in Rosenblum's style, which weds the unusual pitches to a jazzy idiom, clever orchestration and a highly engaging sense of form. Rosenblum's music demands to be admired, yes, and even aspires to be loved, but it's also surprisingly easy to like.