Over four previous albums, New York's Gutbucket have established themselves internationally as a no-holds-barred Rock in Opposition-cum-avant-jazz act that plays an unrelenting, sophisticated brand of composed and improvised music driven by an aggressive use of dynamic force and sly humor.

During their decade-plus tenure, the group's members have all become noted composers, working on film scores and collaborating with dance troupes and forward-thinking classical chamber ensembles.

Gutbucket's individual members display these talents by writing for the ensemble specifically, and Flock is their most provocative album -- which is saying plenty -- but it is also their most antagonistically accessible.

Each member -- guitarist Ty Citerman, saxophonist and clarinetist Ken Thomson, bassist and cellist Eric Rockwin, and drummer and percussionist Adam Gold -- focuses intently on tightly arranged yet sprawlingly adventurous tunes, beginning with Thomson's "Fuck You and Your Hipster Tie." Commencing with dissonant stop-and-start exchanges between clarinet and soprano saxophone, electric bass and drums, the tune soon emerges with an expansive melody against a mathy guitar rock backdrop.

Lyric repetition occurs in spurts: a cello enters briefly as the harmonics begin to spiral upward, grounded only by power chords and a bassline.

The long intro to Citerman's "Murakami" sounds almost post-rock before rim shots and baritone and alto saxophone create an elegiac, expressionistic melody that quietly and moodily creeps through it, cymbal sounds emerge from the ether and eventually conclude with a guitar that simultaneously suggests "21st Century Schizoid Man" and early recordings by Neurosis.

The tension builds -- and explodes -- in a complete boil.

Wurlitzers, clarinets, electric guitars, and bubbling basslines just under a double-timed drum break fuel Gold's "Tryst'n Shout," a tune that suggests material from Brand X's Moroccan Roll, Soft Machine's V, and Mission of Burma's Vs simultaneously.

The set closes with a three-part suite by Rockwin.

The first two parts, "Dyslexic Messiah (Where's Your Dog?)" and "Sacrificial Vegan," mirror one another in rock-versus-jazz-versus-classical opposition.

The final part, "Turning Manischewitz into Wine," erases these divisions with references to klezmer, heavy metal, and free jazz.

Flock is an exciting ride, full of fine ideas, terrific arrangements, quizzical moments, explosive surprises, and drop-dead killer execution.