Five producers, including Rage Against the Machine's Tom Morello and Limp Bizkit's Fred Durst, helped Primus with its latest album, but they haven't significantly altered the San Francisco trio's sound, an ungodly amalgam of Frank Zappa, Rush and the Red Hot Chili Peppers. Old pal Tom Waits (who appeared on the band's "Sailing on the Seas of Cheese") brings Brecht-Weill's oom-pah-pah rhythm to the one song he supervised, "Coattails of a Dead Man," but the other collaborators (who include Morello and Metallica's James Hetfield on guitar and Tricky's Martina Topley-Bird on vocals) had limited influence. "I drink Campari/With marinated wild hog/I've no sense/I lick electric fence," claims singer-bassist Les Claypool in "Dirty Drowning Man," the sort of self-amused boast that proves the band is still (as Claypool sings later in the same song) swimming "these seas of cheese."

The quintet's name suggests death-metal and its lineup (which includes a "turntablist") promises metal-hop, but Incubus offers none of the former and not much of the latter. Instead, this California band's sound is modeled on the introspective verses and explosive refrains of grunge. Such songs as "Consequence" and "Drive" express their post-adolescent yearning primarily with Brandon Boyd's vocals and Mike Einzinger's guitar, and even the beat-oriented instrumental "Battlestar Scralatchica" and the drum-and-bassed "Pardon Me" don't significantly alter the album's style. Boyd's lyrics are ungainly and so rhyme-driven that they border on the comic, but Incubus' earnest, melodic hard rock is preferable to another album of corny Satanic shtick.

Primus's Claypool sings on "The Ballad of Buckethead," but that's one of the few vocal tracks on Buckethead's fifth solo album, "Monsters and Robots." Accompanied by electronic percussion and various guests, the pseudonymous guitarist demonstrates his jazz-funk-rock skills on such tracks as "Night of the Slunk" and "Stick Out," whose playing is formidable but soon wearying. "Monsters and Robots" often resembles an Adrien Belew album without singing or songs, which is to say it's strictly for devotees of speedy, shrill punk-funk guitar.

All appearing Sunday at the 9:30 Club.

To hear a free Soundbite from Primus, call Post-Haste at 202/334-9000 and press 8107. For a Sound Bite from Incubus, press 8108. For a Sound Bite from Buckethead, press 8109. (Prince William residents, call 690-4110.)