The Canadian composer John Oswald’s professional reputation is built on Plunderphonics, an album that was never officially available for sale. Most of the original copies were destroyed, but 12 years after its original non-release, it’s been expanded to a double-CD retrospective called 69 Plunderphonics 96 that is finally available for over-the-counter purchase, though the circumstances are a little dubious.

The original Plunderphonics is almost entirely collages made of other people’s recordings, jackhammered into tiny chunks and rearranged until the quotes are recognizable but the form isn’t. One piece rearranged Michael Jackson’s “Bad,” another slowed down Dolly Parton’s “The Great Pretender” until her voice sounded male, a third turned 10 seconds’ worth of splinters from the Beatles’ “Birthday” into a new instrumental. Several hundred copies of the disc were distributed free (and widely duplicated), but thanks to legal action from the Canadian recording industry, the master tapes and the remainder of the pressing were crushed.

By then, though, the word was out, and as everyone knows, having your artwork banned is the surest sign that you’re on to something. Oswald went on to a series of commissioned works (mostly excerpted on the new set). Rubaiyat was a cut-up of bits of the Elektra Records catalogue produced for the company’s 40th anniversary; Grayfolded was a massive two-disc mosaic based on the Grateful Dead’s “Dark Star”; Plexure took the plunderphonic æsthetic to a near-terminus, cutting up its source material into pieces so small that their timbre was the only way to recognize them. One of its highlights appears on 69/96: “cyfer,” which was mostly Fine Young Cannibals’ “She Drives Me Crazy” divided into split-second fragments, with a “chorus” grafted on from a purée of the first second of Eurythmics’ “There Must Be an Angel.”

What started as a one-off gag has turned into a substantial body of work, and Oswald announced a few months ago (or claimed, anyway) that he planned to release his major retrospective on his own Fony label, as a two-CD set with a $100 price tag to cover all its associated licensing fees. The story goes that when some of the important licenses fell through, Negativland’s label Seeland stepped in, stole a digital copy of the 69/96 recordings and artwork, and bootlegged the thing (with a new sticker price a third of the intended one). “I am happy to do nothing to prevent them from following through with this scheme,” Oswald comments dryly in a press release.

The main body of Oswald’s cut-up work is from the ’80s and ’90s, and listening to it is exhausting. “I prefer to distill out the redundancy in music,” he notes in the accompanying booklet (in which nearly every name is accompanied by its anagram — Jerry Lee Lewis becomes Sir Jewelry Eel, Elvis Presley is Sleepy Silver), and the repetition of grooves and hooks and choruses that’s at the heart of most pop music is as redundant as, say, water is in food. What’s left when it’s distilled out is more concentrated, but also tougher, and unpleasant. One exception in the set is an early piece called “power” built from a looped Led Zep riff with a radio preacher over the top. It evidently predated the anti-redundancy dictum.

There are some nice conceptual gestures, like “z24,” 24 recordings of Also sprach Zarathustra arranged so that the big horn entry is in synch and nothing else is, but the aggressive hyperstimulation never lets up: cross-references, sudden speed-metal assaults, indiscriminately deployed verbal and musical puns. In 69/96’s opener, “btls,” the last chord of “A Day in the Life” is augmented with the first chord of “A Hard Day’s Night.”

Oswald is incredibly good at what he does; of all the sound-collage artists operating at the moment, from hip-hop samplers to academic timbre wonks, he’s the cleverest and his work is the most labor-intensive. And he’s got outlaw cachet — there’s the thrill of the forbidden about its détournements of familiar sounds. But whether it’s legal to release 69/96 without permission from copyright holders has no bearing on its value as music. (Whether it’s ethical may be a different story.) In fact, the set’s most serious flaw is that its art is entirely referential. So, unless you recognize the references, Plunderphonics is incapable of revealing its intended meaning or giving pleasure. That doesn’t invalidate it as music. But the album has more in common with music criticism than with music itself.