Guitarist Raoul Björkenheim wields his instrument like a knife on the ironically double-entendred Apocalypso. Sometimes he stabs, other times he engraves; or he might twist and jab, or simply scratch. Maybe it's just a Finnish thing, but brightness and Björkenhim just don't go together. The story behind this composition is relatively brief: in 1994, the Helsinki Juhlaviikot Festival commissioned him to write a piece for a hundred guitars. They managed to compromise at 42 musicians instead. His group performed Apocalypso live on film for the big event.

But then the guitarist sat back and decided to beef up the original 24 minute performance, yielding this recorded version of 41 minutes' duration. Björkenheim plays all 42 parts. Rest assured that Apocalypso does not once relent in intensity, even if quiet moments pop up occasionally. It's something of a testosterone-rich performance, remarkable in the fact that he managed to accomplish the thing at all (given its complexity, and insisting on handling all the axes himself). Ever since his appearance on Krakatau's landmark debut, Ritual, in 1988 (a true masterpiece of guitar experimentalism), Björkenheim has made himself known as something of a rebel. He refuses to engage in any of the ritual cliches certain other Berklee guitarists have adopted wholesale. Instead, he adopts pounding tribal rhythms as a foundation for otherworldly excursions on the high end. Always elusive, he uses every tool at his disposal to color notes: vibrato, muting, bending, harmonics, scratching, and effects of all flavors. Those colors just happen to be penetratingly dark, but that doesn't subtract a bit from their impact.

Apocalypso is nominally a suite of nine parts, which segments appropriately into different angles of approach. He may enter into a temporary dream state (nightmarish in nature, of course), as on "Spirits." Or he might assemble a squad of coordinated piledrivers for the heaviest dark metal you've ever heard, as on the intro to "Circles." It's very hard to predict what's coming next, and that's part of what makes this disc work so well. The other great feature is that the composition seems quite flexible at times in terms of execution, at least for lead voices. Björkenheim's "solo" lines wiggle and squirm, twisting and winding their way along uncharted territory. There's no bluesy strut, no tempered swing, no polite call-and-response anywhere on Apocalypso. (And absolutely no calypso whatsoever.) Even the most pensive moments—like "Lament," the track before the piledrivers set in—have a sense of foreboding.

A most unusual disc, Apocalypso manages to be both brilliant and apocalyptic at the same time. It stands among Björkenheim's best work, in part because he took charge of the performance and production. What you hear here is pure, undiluted Björkenheim. And it's truly glorious in its relentless blackness. With 42 voices, it's got the depth to really penetrate. Like a knife.