On the surface, all Primus albums seem to sound alike, especially to outsiders (read: anyone who either respects the group but doesn't get them, or the minority that actively hates them, particularly Les Claypool's demented comedy schtick).

That's not really true, even if the same basic elements remain in place each time, no matter who is in the band.

And Primus has never tried to shake things up as much as they do on their seventh album, AntiPop.

Primus enlisted a dizzying array of collaborators -- Stewart Copeland, Tom Waits, James Hetfield, Tom Morello, Jim Martin, Matt Stone, Martina, and Fred Durst among them -- all in the purpose of challenging themselves to find different dimensions to its music.

Some play or sing, some produce, but it's amazing how much each individual guest changes the tone of the music.

It's not always for the best, but it keeps things fresh, if not necessarily coherent.

Though there are a couple of good lyrics here, this is by and large an album about music; it would have been even better if it had been primarily an instrumental album, actually, since the vocals get in the way occasionally.

By now, the popping bass, dissonance, and angular riffs don't seem like schtick, but the lyrics and singing do.

Still, it's possible to get past those and hear AntiPop as one of Primus' most ambitious and best efforts.

No, they're not always successful, but no two songs sound the same, and some collaborations are among the best things Primus has ever recorded.

AntiPop is dense music that isn't afraid to be goofy or fall on its face -- and even if it's not to your particular taste, it's hard not to respect this.