An hour earlier, I was sitting backstage with the McDades musing over possible definitions of their music. Now I was seeing them in action, a Sunday night performance at the Festival Club that made a description ever harder to nail down.

The quintet from Alberta was completely rocking out on acoustic instruments, building an organic groove that flitted and flowed and ricocheted around the room. The pinnacle of their performance was an improvisational jam that was constructed (or did it just grow, completely free of design?) before our wondering eyes.

Jeremiah McDade kicked the lengthy number off with the best funky didgeridoo imitation I've heard. (He later told me it was actually an example of Tuvan throat-singing from upper Mongolia, but it still sounded like a didge to me.)

The set featured an intricate dialogue between fiddle and flute. Solon McDade was rocking hard on the upright bass, while Shannon was playing a sinuous fiddle; it looked like bellydancing might be imminent, although it never occurred.

There was a bit of a guitar and percussion melee, executed at the hands of non-siblings Simon Marion and Eric Breton, before Solon and Jeremiah held a lengthy discussion on the bass and soprano saxophone that seemed to roam over diverse topics such as life, poetry and Moroccan cuisine. Then everyone jumped back in for a potent melange of music that powered through to the end.

You got the feeling the music was coming to life, fresh and glistening from the womb, right before your eyes, and to some extent it was. The bandmates said later the melody was established in advance, but everything else came together as they went.

It was, as of that night in the Festival Club, a tune with no name. It was a little exhausting just to watch, and a lot exhilarating. I hope they record it, but I'm not sure they can; some things just aren't meant to be confined.