Portishead may not have invented trip-hop, but they were among the first to popularize it, particularly in America. Taking their cue from the slow, elastic beats that dominated Massive Attack's Blue Lines and adding elements of cool jazz, acid house, and soundtrack music, Portishead created an atmospheric, alluringly dark sound. The group wasn't as avant-garde as Tricky, nor as tied to dance traditions as Massive Attack; instead, it wrote evocative pseudo-cabaret pop songs that subverted their conventional structures with experimental productions and rhythms of trip-hop. As a result, Portishead appealed to a broad audience -- not just electronic dance and alternative rock fans, but thirtysomethings who found techno, trip-hop, and dance as exotic as worldbeat. Before Portishead released their debut album, Dummy, in 1994, trip-hop's broad appeal wasn't apparent, but the record became an unexpected success in Britain, topping most year-end critics polls and earning the prestigious Mercury Music Prize; in America, it also became an underground hit, selling over 150,000 copies before the group toured the U.S. Following the success of Dummy, legions of imitators appeared over the next two years, but Portishead remained quiet as they worked on their second album.