Bass, drums and trombone are not common instrumentation for a trio. But intermittently for thirty years, bassist Mark Helias, drummer Gerry Hemingway and trombonist Ray Anderson have explored exactly this format under the apt moniker BassDrumBone. Their eighth CD, The Line Up, exemplifies the approach they have honed as a trio. It is not a typical horn-plus-rhythm trio, nor a free-form blast of notes or examination of textures and extended techniques. Instead, it is a well-balanced, cohesive collective. Each member brings thoughtful compositions that highlight the abilities of the other members, who seamlessly shift roles between support and soloist with deft malleability.

Anderson’s ‘bone leaps to the fore on his composition “Insistent,” which also describes Helias’ pulsing groove, punctuated by Hemingway’s judicious snare stabs and graceful ride. His martial snare roll spurs Anderson’s finale, setting Helias in motion, the trombone returning to comp a drum feature before the tune glides back to the head.

The music is often episodic, and the compositions take dramatic shifts as they unfold. Hemingway’s “Rainbow” begins impressionistically with bowed bass, shimmering cymbals and long trombone tones before the rhythm settles in with a melodic bass line supporting Anderson’s flugelhorn-like sound. The title track, composed by Helias, is propelled by a Mingus-like bass line doubled by Anderson, until it shifts to a walking feel under a growling, plunger-muted trombone solo. The bass and drums intuitively quicken and retract the pace and share a frenetic exchange, with a bit of trombone coloring.

The electric bass guitar offers a different texture on “1,2,3,” almost necessitating a funkier groove that drives the form of the piece, a highlight for a melodic tom-tom flurry by Hemingway. These tonal shifts and the variety of styles referenced here keep the music fresh and unpredictable, as does the musicians’ familiarity with and confidence in each other.