Beauty, in its capriciousness, is not always opposed to the ostensibly ugly. Composers like Wagner and Debussey valued dissonance even in their most sweeping works. So did the free jazz movement in the 1950s; its practitioners emphasized tone over melody and a break from the rigidity of prevailing jazz forms and, in so doing, wove songs that were both cacophonous and exquisite. Broken Social Scene, the Toronto collective that played the Levin Ballroom last Monday, conjures similar dichotomies in its music-it is orchestral and delicate, yet vociferous. That was apparent in "Ibi Dreams Of Pavement (A Better Day)," which closed the band's main set. The song played like entropy in a womb: Guitars and brass whirlwinded violently, the vocals-spat violently into the microphone by ringleader Kevin Drew-clawed at the audience's ears as though desperately hoping to transcend higher frequencies and planes of existence while the band members looked skyward in a moment of hard-fought-toward catharsis. It was a racket-a beautiful and unrelenting mess.

For the bulk of the band's hour-plus set, the noisy half of that equation seemed to dominate the group's usually ornate sound. On past tours and in the studio, Broken Social Scene's lineup included violins, horns, glockenspiels and layers of tense, competing vocals; here, the band consisted of a mere seven members, its sound unusually guitar-heavy as a result.

The show was also the first of Broken Social Scene's current tour and, as such, the typically controlled band-it makes chaos with care-sounded noticeably unhinged. For the most part, this was a boon. A souped-up version of "Major Label Debut" from the To Be You and Me EP was refreshing and anthemic; that Drew's guitar was out of tune throughout, as he conceded with slight embarrassment toward the set's end, was inconsequential.

Many of the best moments, however, were not the most immediately noisy, but instead started ethereally and swelled to grand climaxes. A medley of "Late Nineties Bedroom Rock for the Missionaries" and "Shampoo Suicide" was a particular highlight. The first half was mostly instrumental; only Drew's occasional falsetto squeals punctured its deliberate, post-rock melody. It soon ballooned, first as a pleasant tropical break, then into a whirling, clamorous crescendo in which the band resembled an indie-rock Sly and the Family Stone. Like that soul collective, the Scene's principals interwove strained vocals but never quite harmonized while its backers blended disparate genres in one seamless and cohesive gesture.

The band later channeled another aesthetic cousin, the noisy indie giants Dinosaur Jr., with a well-chosen cover of "The Wagon" during its encore. But the song, like a number of others, seemed lost on the audience, which-perhaps due to persistent sound problems or the evening's overall messiness-remained largely motionless.

This was a shame. The show was a fascinating exercise, watching a band-typically as conscientious on stage as in the studio-let loose with such abandon. The members' humors mirrored their songs: They stumbled in pronouncing Brandeis correctly and bantered about their failure to do so; Drew and singer Amy Millan-for her day job, she fronts the band Stars-joked about meeting in drama school; bassist Brendan Canning feigned rock-stardom during "7/4 (Shoreline)," executing several "rock kicks" and yelping erratically.

While Monday's set was loose and sprawling and imperfect, it was also a treat. What it wasn't was any close approximation of Broken Social Scene's studio sound, which, for its lushness, has established the band among this decade's most important. That was O.K. Sometimes there's greater beauty in sheer-and fabricated-chaos.