This CD was an event. Une théorie des ensembles was the first live album from Ambiances magnétiques (the label) in almost 10 years of existence. It was also the only album ever to be credited to Ambiances magnétiques (the artists’ collective). Recorded on February 7 & 8, 1992 at the Maison de la Culture Frontenac in Montréal, this CD presents performances from all eight members of the collective at the time (founders René Lussier, Jean Derome, André Duchesne and Robert Marcel Lepage}; 1986 inductees Diane Labrosse, Danielle Palardy Roger and Joane Hétu}; 1988 last addition Michel F Côté — Martin Tétreault would join later in the mid-1990s).

The album opens and closes on two ensemble pieces. Ambulances en plastique is a Derome-penned rock fanfare, while Montréal, 7 h a. m. bears a typical rock guitar-driven Duchesne stamp. This fantastic guitarist/composer has worked so rarely in the 1990s every bit of material is a delight to hear. Between these two pieces, five Ambiances magnétiques groups show their chops. Duchesne’s Locomotive plays fair renditions of three tracks off its CD. Côté’s Bruire delivers two very nice improvs going in the same direction as the second album Les fleurs de Léo. There are also two tracks from the all-girl group Justine, mostly improvised although the first one is recognizable as Vidanges Domestiques (thanks to the quirky melody), off their last CD Langages Fantastiques. The album’s highlight is Les Granules’ 13-minute suite Le bizarre échevelé, a never-recorded piece and the last thing Lussier and Derome’s duo put on disc. The two tracks from La Flore laurentienne are the only crumbs remaining from this Lepage project — and it’s a pity: very good blend of extended clarinet techniques and a more rock/techno approach. Overall, Une théorie des ensembles is a very enjoyable CD that adds valuable material to these artists’ discographies.