If it weren't for G.B.H., hair metal might still be around. Grievous Bodily Harm, better known as Charged G.B.H., was one of punk's first crossover bands. Its 1981 debut album, Leather, Bristles, Studs, and Acne, won the group an international punk following, thanks to its blurry guitar work and gruff vocals. The quartet's real breakthrough, though, came in 1984 with City Baby Revenge, on which the band developed its trademark sound: sweeping speed-metal rhythms coupled with a thundering double-bass bedrock, perfectly merging punk rage with Sabbath-style production. This precursor to speed metal, which favored musical substance over style, was later refined on Oh No It's G.B.H Again, an album that influenced bands ranging from Megadeth, Metallica, and Slayer to Nirvana and Rancid. By 1989, G.B.H. had dropped punk rock altogether and produced a trio of forgettable heavy-metal records. Nearly a decade after that unfortunate decision, however, the band returned to its roots with Punk Junkies, an album packed with punk rock aggression. The 1997 release is easily G.B.H.'s best work since '86's Midnight Madness and Beyond: Songs like "Civilized," "Tokyo After Dark," and "Stormchaser" sound like lost tracks from a recording session 15 years ago. The current G.B.H. tour offers a chance to witness the band that proved three-chord punk rock was too ambitious, and that zebra-striped hot pants had to go. Billy Club opens at 7 p.m. Wednesday, followed by Against All Authority and 98 Mute at the Maritime Hall, 450 Harrison (at First Street), S.F. Admission is $10-12; call 974-0634.