The brainchild of percussionist John Hollenbeck, the Claudia Quintet has navigated the boundary lines between free jazz, contemporary composition, progressive rock and electronica so successfully that its output is virtually uncategorizable. For, the aptly titled fourth album from the ceaselessly inventive group, offers a slight departure from its last record.

Semi-Formal (Cuneiform, 2005), used brief minimalist interludes to segue from one tune to another, much like a suite. Less conceptually arranged, this album is comprised of a varied selection of tributes, with Hollenbeck dedicating each tune to a personal inspiration.

Hollenbeck is joined by the regular Claudia line-up of clarinetist/tenor saxophonist Chris Speed, accordionist Ted Reichman, vibraphonist Matt Moran and bassist Drew Gress. Alternating jovial melodies and captivating rhythms with bittersweet lyricism and somber reflection, the acoustic quintet spins otherworldly sonic tapestries that occasionally mimic electronic effects.

A Claudia first, "For You," uses prepared electronic tape and sporadic spoken word to paint a minimally atmospheric tone poem unlike their previous work. Conceptually isolated, it contrasts with the album's inspired hybrid of complex rhythms and intricate harmonic counterpoint.

Such elaborate ebullience can be heard immediately on the opener, "I'm So Fickin' Cool." Relentlessly upbeat, the tune seamlessly escalates from modish post-rock funk to Klezmer-inspired celebration. Gress' subterranean bass line is accented by Moran's scintillating vibraphone accents as Hollenbeck's accelerating tempo whips Speed and Reichman into a polyphonic frenzy of caterwauling clarinet and pneumatic accordion. "Be Happy" is a dense mosaic of symmetrical polyrhythmic drive and interlocking harmonic counterpoint. Cerebral but not stuffy, the tune builds to a rousing anthem delivered with a zeal worthy of its title.

The propulsive, roiling free jazz of "Rug Boy" is balanced by the languorous bluesy lilt of "This Too Shall Pass" and the spirited, minimalist chamber excursion “August 5th, 2006." With mercurial irreverence, Hollenbeck fuses The Carpenters' bittersweet melody "Rainy Days and Mondays" to Stan Kenton's bouncy arrangement of "The Peanut Vendor." The closer, "Three Odes: Admiration, Nostalgia, Pity" sweeps gracefully through a series of understated moods, succinctly encapsulating the quintet's capabilities.

A fertile blend of infectious grooves, euphonious melodies, rich harmonies, adventurous improvisation and cinematic ambience, For is another winning chapter in the saga of the peerless Claudia Quintet.