OTTAWA - We had been promised a seven-man Broken Social Scene. Stripped-down, by BSS standards.

But then, on a night that had promised thunderstorms but delivered a perfect late-summer evening, all bets were off.

That was demonstrated early in the Toronto-based collective's headlining Main Stage set yesterday, as Stars star Amy Millan was brought onstage to join an eight-man combo for an incendiary reading of 7/4 (Shoreline) from the expansive collective's 2005 self-titled album. Millan would come and go, as is a BSS member's wont, throughout the set.

We had also been promised a set heavy on material from co-founder Brendan Canning's recent solo release, with only an occasional contribution from fellow stalwart Scenesters Kevin Drew and Andrew 'Apostle of Hustle' Whiteman. But, again typically of BSS, the set was a largely democratic affair, each frontman visibly revelling in accompanying the others.

It was a welcome return for the band, not-unreasonably introduced as "the patron saints of Canadian indie-rock," that previously headlined the Ottawa Folk Festival four years ago.

That appearance marked a significant break from the festival's decade-long relatively narrow definition of 'folk music' -- i.e. acoustic instruments and singalongs. And yesterday's show found the group greeted by a sizable crowd as old friends.

As were, on the nearby Hall Stage, The Carolina Chocolate Drops, whose oldtime music sounded every bit as fresh as that of our indie patron saints. The Dance Tent, meanwhile, offered stiff competition with Jerry Douglas and a cast of over a dozen virtuoso players jamming to bluegrass gems. Rarely, at any local festival, has it been more difficult to pick just one stage.

If, when the dust settles, this year's festival belongs to The Carolina Chocolate Drops, last night ultimately belonged to Broken Social Scene, a formidable opponent that not so many years ago revolutionized Canadian pop music. And a certain folk festival.

Earlier in the evening the audience had been treated to an admirable dose of variety, from the tender songs of Ana Miura through bona fide folk music from autoharpist Bryan Bowers -- perhaps the only man to have earned a distinguished place both in the Autoharp Hall of Fame and on a Dr. Demento compilation. Bowers' instrumental showcase was followed by Douglas and his crack band of Nashville veterans who upped the ante considerably.

Fortunately, Broken Social Scene, as always, had a number of aces up their collective sleeve. And played each card beautifully.