Long established as the most accessible act in contemporary prog-metal, New York's Dream Theater is probably more accurately described as a hard rock band whose members just happen to know how to play the shit out of their instruments. Prog's defining tendencies toward nutty arrangements, obscure classical influences, and multiple stylistic shifts generally take a back seat to cohesive songcraft with this group. Sure, it's epic and it shreds, but the bombast is almost always anchored to memorable melody. Technical brilliance aside, the band's most tangible ties to the prog community are its refusal to kowtow to ephemeral kid-metal trends and the obsessive, bootleg-swapping attentions of its fans.
Swedish outfit Opeth, on the other hand, has always been associated with the death and black-metal niches, despite its forward-thinking incorporation of classical melody and acoustic instrumentation. In 2003, the band made a bid for mainstream exposure with its seventh CD, Damnation, but diehard fans rejected the kinder, gentler Opeth and the band returned to its complex, dynamic pummel in 2005 with Ghost Reveries. Chaotic (read: impenetrable) North Carolina post-hardcore unit Between the Buried and Me and wildly eclectic New York groove-metal combo 3 round out a brutally varied bill.