Progressive Metal blends the attack, volume, and aggression of metal with the grandiose, pseudo-classical ambitions of prog-rock. Of course, certain bands emphasize one influence over the other -- Dream Theater, for instance, leaned toward prog more than some of their peers -- but they all shared this one basic ambition. Progressive metal first surfaced in the late '80s, led by such bands as the Pink Floydian Queensryche. At the time, prog-metal was fairly underground (although such Metallica albums as And Justice for All were as dense and layered as prog albums), and it remained that way throughout the '90s. However, it was popular enough to produce a handful of crossover hits, most notably Queensryche's "Silent Lucidity." But even though it never became a huge seller in the '90s, progressive metal always had a dedicated following, and bands like Queensryche and Dream Theater stayed on major labels throughout the decade. By the end of the '90s, however, it was firmly the province of hardcore fans.