Return of the antidiva: gay fans welcome the latest from the brilliant Bjork.

Bjork is the weird gay's Kylie. She's the preferred diva for a specific subgroup of homosexuals, namely the kind who think they're too cool to have a diva, and their devotion is slavish. The princess of mutant Icelandic pop decides to release, all at once, four live CDs and accompanying DVDs? No problem. Scalpers charge $400 for tickets to her tour? Pay it. Her fans follow her down any path she takes.

And what paths they are. Her detractors complain that her attachment to pop music is tenuous at best, that her compositions lack structure, and that her idiosyncrasies are too alienating. More often than not she proves them right, stretching and beating the genre to a formless gee, creating head-scratch-inducing songs like the Oscar-nominated "I've Seen It All" or overseeing remixes of her own album tracks that end up taking the aural shape of a crashing metallic robot war, only to turn around and create an entire album of hushed, delicate tunes on her last release, Vespertine. Of course, all these choices only further cement her standing for her fans. For them it can't get strange enough.

Which is why Medulla succeeds. Once again the tiny woman in the dead-swan dress has awakened from a crazy dream and made a soundtrack for it, this time abandoning even the idea that one might need some musical instruments to do such a thing. Almost entirely a cappella, Medulla is the logical next step after the smallness of Vespertine. Mostly composed of Bjork's layered vocals and growls, tongue clicks, and sighs, the sound gets large only when she's joined by Eskimo choirs, or as on tracks like "Triumph of a Heart" by Japanese human beat-box master Dokaka--a man who's been known to create cover versions of "Smells Like Teen Spirit" and Metallica's "Creeping Death" with his mouth. And even then, the intimacy of it all makes Vespertine sound jarring and rude. It's full of hit songs, albeit ones for a very personal, very secret Top 40: one where "strange" trumps "normal" and pop's definition is still happily up for grabs.