OTTAWA - It was one of the most perfect summer concert nights of the year, if not all that imaginative or groundbreaking.

Blue Rodeo, a Canadian institution if there ever was one, took the main stage of the Ottawa Blues Festival under a gently darkening sky, the familiar harmonica chords of What Am I Doing Here melting over a laid-back, beer-drinking crowd of 20,000 along with the warm breeze.

Festival Plaza was more packed than ever for the homegrown favourites, who turned in an utterly predictable show in the best sense of the word.

Singer/guitarist Jim Cuddy, belly presumably full from an earlier Italian feast at Metcalfe St. eatery Tosca, was his mellow best, side-by-side with longtime collaborator and silver-haired counterpart Greg Keelor.

"Have we mentioned how great you are?" he said. "We can't mention it enough."

The ease with which the pair bend into well-worn and much-loved tunes like Heart Like Mine -- which boasted a nice a cappella intro -- is just evidence of their 20 years of partnership.

It's mind-boggling, actually, that a group like this could lose and gain members, most of them filing solo efforts, and still like each other enough to play the same old songs, over and over again.

The six-strong group stuck to old favourites while making some effort to shake things up, though I couldn't help but miss the horn section that accompanied them on the road after 2002's Palace of Gold.

They played a protracted, slightly sluggish version of Five Days in May, from 1993's Five Days in July, that whipped up into a tasty, slightly unexpected instrumental jam of a noisy finale. They did a good job of establishing a pleasing cadence, with essential numbers like Lost Together mesmerizing the romantics in between more upbeat and energetic tunes like Till I Am Myself Again and Diamond Mine, complete with a rock show-worthy, frenzied finale.

The boys brought out Matt Mays, who played the night before with El Torpedo, for a nice version of the old tune Just Like Tom Thumb's Blues during an encore that included a crowd-infused rendition of Try,off 1999's Just Like a Vacation.

In the end, as is the challenge of every group tasked with playing to such an enormous crowd, Blue Rodeo failed to captivate all the way back to the lemonade stand during the hour-and-45-minute show.

Doesn't matter.

Bluesfest organizers had the best main-stage night of the festival from those Toronto boys. It was a bread-and-butter, meat-and-potatoes show, chock full of the group's well-honed blend of country-folk-rock. The happy crowd just lapped up whatever goodness Cuddy et al had to offer.