Few rock groups can claim to have broken so much new territory, and maintain such consistent brilliance on record, as the Velvet Underground during their brief lifespan. It was the group's lot to be ahead of, or at least out of step with, their time. The mid- to late '60s was an era of explosive growth and experimentation in rock, but the Velvets' innovations -- which blended the energy of rock with the sonic adventurism of the avant-garde, and introduced a new degree of social realism and sexual kinkiness into rock lyrics -- were too abrasive for the mainstream to handle. During their time, the group experienced little commercial success; though they were hugely appreciated by a cult audience and some critics, the larger public treated them with indifference or, occasionally, scorn. The Velvets' music was too important to languish in obscurity, though; their cult only grew larger and larger in the years following their demise, and continued to mushroom through the years. By the 1980s, they were acknowledged not just as one of the most important rock bands of the '60s, but one of the best of all time, and one whose immense significance cannot be measured by their relatively modest sales.