For the Portland Cello Project, collaboration is the name of the game. Over the past few years, the traveling troupe of Portland cellists have created backing tracks for The Builders and The Butchers, Laura Gibson, Loch Lomond and pretty much every other buzzed-about band in the Rose City. The PCP writes few completely original tracks; instead, the 10-cello orchestra works to accompany other musicians live or on record, sometimes rearranging songs in the process. Lately, the ensemble has managed to expand its reach well beyond its eponymous hometown. The PCP signed to Kill Rock Stars last year and is pairing with Thao with the Get Down Stay Down (and a few other bands) on a new record. The combination has created a totally different sound for lead singer Thao Nguyen: A song like "Tallymarks" is slowed down to an almost lilting pace; Nguyen's sultry vocals are checked by the cello's sonic earful. It's proof that 11 heads can be better than one. All ages.