This summer L7 harassed the Lilith Fair and Warped tours by flying self-promotional airplane banners to expose the narrow gender and stylistic boundaries of the line-ups, but their sixth album, "Slap-Happy" (the first on their Wax Tadpole imprint for independent label Bong Load), fails to follow through on the implied artistic challenge.

Instead, songwriter/guitarist Donita Sparks continues to craft old-school grunge salvos, adding a few surprises to the musical bark but little lyrical bite. "Crackpot Baby," "Rockin' Machine" and "Mantra Down" rock menacingly; "Lackey" adds her trademark sardonic humor and sing-along chorus; and "Livin' Large" turns to gentle, sassy pop -- closer to Luscious Jackson than metal head, a transformation completed with the hip-hop-spiced "Freeway." While it's refreshing to hear the band experiment, the lighter songs drag with repeated riffs. Sparks grows more serious on "Stick to the Plan," mocking phallocentric rock culture -- as well as her own critical limitations. But the strongest feminist statement comes from guitarist Suzi Gardner's "War With You," a sludgy anthem that laments the necessity for women to pull their punches in dealing with men.

When Sparks tries out a sensitive delivery on the almost coy indie-pop "Freezer Burn," her oblique lyrics conspicuously mark a missed opportunity to make a deeper statement. "Slap-Happy" won't disappoint those who want to rock, but it doesn't pick up the gauntlet L7 lays down in other arenas.

Appearing Tuesday at Black Cat with Ink & Dagger and Vanity Champ. To hear a free Sound Bite from L7, call Post-Haste at 202/334-9000 and press 8111. (Prince William residents, call 690-4110.)