Adjunct to the Whitney Museum of American Art in New York City is the Whitney at Altria, a cavernous space located in the floor-level lobby of the Altria Group, Inc., a parent company of both Phillip Morris and Kraft Foods. The building sits directly across from Grand Central Station, and two of the lobby's four walls are entirely made of glass so that, as audiences watch film screenings and performances, commuters emerging into the city watch them, and vice versa. I was there a few weeks ago to watch Mick Barr perform as his alter-ego Ocrilim (his other, more prominent outfit, is Orthrelm, a guitar and drums duo), whose newest release is Anoint. Sharing the bill with Barr in this particular screening series were works by Dan Graham, Bruce Nauman, Jim O'Rourke, and Steven Prina, among others; all figures who exist, to varying extremes, in the murky territory carved out by those who work as both artists and musicians.

Barr to my knowledge has never made anything but music, nor has he ever deliberately written music for a museum, installation, or other explicitly "art" purpose. This has not prevented fans and reviewers alike from considering him in traditions of minimalist painting and sculpture (as Dominique Leone did here last year); classical music and modernist musical minimalism (as Joe Gross did, in 2002, in The Village Voice); and in his most natural home, in the pop-music avant-garde (as Andy Beta did, in a recent City Pages review, implicitly comparing Barr's work to that of Lou Reed).

What all this gets at is the fact that Barr's work doesn't fit in anywhere easily. Listening to Anoint, I spot traces of it in places as diverse as an Alex Ross description of Shostakovich (the composer's "inclination toward grandiosity and brutality, his perverse manipulations of form, his habit of freezing harmonic movement while a seemingly trivial motif repeats maniacally"), the cartoon horror-soundtrack metal of Relapse two-piece Zombi, and on a couple different subway platforms. But lets not glamorize Barr either. Ocrilim sounds like a man playing flurries of single notes on a lonesome guitar. It is technically stunning, compositionally deep, and the sum of its parts.

Anoint, though divided on CD into seven distinct tracks, is a singular long composition. It begins without ceremony, incoherently; Barr plays a seemingly unrelated steady stream of high-pitched notes, maybe only one step up from a warm-up or the prelude to an improvisation. Then, a minute in, the playing locks up, and the piece truly begins: repetitive phrase after repetitive phrase, the particulars varying and then disintegrating into the next. Those familiar with Barr's work will know how quickly his ideas come and go: Orthrelm's Asristir Veildrioxe contained 99 discrete tracks in less than 15 minutes, and an earlier Octis (another Barr alias) work, Uppragn Srilimia Ixioor Ocrilm Nollfithes Mrithixyl, had an only slight more modest 72. As with those, Anoint requires dozens of listens just to begin untangling its structure.

Less riffs than a continuous stream of sound modulated by Barr's blurring fretwork, Anoint hovers around a mildly ominous theme, a sort of insistent declaration of arrival or impending doom or a merely a simple celebration of the way these particular notes join together. Individuated riffs come but quickly go, and the overall pattern is so large that it is impossible to step far enough away to completely comprehend. My touchstone for the record, then, came to be architecture. The piece is like an enormous building; the various passages and intricacies of the various movements within explorations of the monolith's layout and passages. Barr is making work in three dimensions.

Ocrilim are taxing, exhausting, and confounding-tributes to its power. Fatigue demands only so many listens before taking a long break. It will not be something I return to often, but that will be out of respect.