These days it’s not so strange to think of the DJ as a musician, and between hip-hop-related artists DJ Shadow and DJ Spooky there’s been enough ink spilled on the subject to fill a few books. But it’s been a iong time coming: In the early 80s, long before the term turntablist came into being, a guy named Christian Marclay was conducting wild experiments with vinyl records that had nothing to do with breakbeats. Physically gluing pieces of different John Cage records together or layering sounds from unrelated records to form jarring collages, Marclay was as important as any hip-hopper in elevating the turntable from playback device to artistic tool. Montréal’s Martin Tétreault, once an experimental visual artist, began working in a similar vein in 1984, and in the last few years he’s released a flurry of fascinating recordings that go well beyond using the record player as a substitute for the sampler—a machine that, by the way, he dismisses because it lacks the serendipitous possibilities of a turntoble, whose output can be radically altered by something as random as a heavy footstep across the room. On Callas: la diva et le vinyle (like most of his work, on Ambiances MagnetiquesI, a duet with Robert Marcel Lepage, he actually plays some discernible passages from recordings by the eponymous opera great and engages in a genuine musical dialogue with the clarinetist, but most of his other recent stuHf is more abstract. He’s screwed with both records and record players, affixing objects to the vinyl or altering the design of the cartridge; he’s even made use of the sound of a turntable’s motor. And he’s a versatile performer: On Dur noyau dur, a duet with René Lussier, he meets the guitarist’s fractured, noisy Derek Bailey-like outbursts with equally disjointed and perpetually surprising eruptions; on 21 situations he answers the slippery electronic fuckery of Otomo Yoshihide with streams of unidentifiable gray sound. And on Île bizarre he counters the drum-machine improvisations of Ikue Mori and the broken-down samples of Diane Labrosse with lowkey noise bursts that eventually make it hard to tell who’s doing what. For his Chicago debut, he’ll improvise with local tabletop guitarist Kevin Drumm, whose recent Second (Perdition Plastics) further develops a unique musical language that no one’s likely to decode soon.