Sound Particle 47 is the second release from veteran Boston-based guitarist/composer Garrison Fewell's Variable Density Sound Orchestra. The group brings together a flexible cast of improvisers from Boston and New York that includes Eric Hofbauer (guitar), Roy Campbell (trumpet), Kelly Roberge (tenor saxophone), Steve Swell (trombone), Dmitry Ishenko (bass), and Miki Matsuki (drums). Sound Particle 47, the follow-up to the band's self-titled 2009 debut (CNM 14), documents both it's continued musical evolution, including new compositions by members of the band as well as frequent collaborator John Tchicai, and it's expansion from a sextet to a nonet.