If nothing else, the veteran jazz bassist Dave Holland sure knows how to form an ensemble. Gracing his quintet on Critical Mass are several esteemed members of the jazz community, including saxophonist Chris Potter, trombonist Robin Eubanks, and vibe and marimba player Steve Nelson. (Drummer Nate Smith is the relative baby of the bunch.) There’s a strong cohesion and fluidity at work across these eight engaging new compositions--four by Holland and one by each of the other players. The spare, slinky, gently loping “Easy Did It,” written by Holland, truly showcases the band’s interplay. Potter and Eubanks twirl their horn lines together like wisteria around a fence, and Nelson is given a chance to stretch out on marimba. Potter’s “Vicissitudes” is a nifty little piece with a skipping, Latin-tinged rhythm and a showcase for Smith’s adroit percussion. “The Leak,” a Smith original, has subtle elements of blues and funk while Holland’s “Secret Garden” is an atmospheric, impressionistic collage that once again highlights the silky interaction among the players. Holland is his usual nimble self--both fleet-footed and rock-solid--but in the end, it’s Nelson’s work on vibes and marimba that gives the music its distinctive sound.