Hi-NRG is a fast variation of disco that evolved in the '80s. Driven by a fast drum machine and synthesizers, Hi-NRG was essentially a dance-oriented music with only slight hints of pop. There would be a few hooks -- generally sung by disembodied vocalists wailing in the background -- but the emphasis of the music, like most dance music, was in the beat. Hi-NRG was a predecessor to techno and house, which drew from its beats in decidedly different ways. House had a funkier, soulful rhythm, while techno expanded with the mechanical beats of Hi-NRG.