Lip-syncing is the musical equivalent of mime and tends to be treated just as harshly as cheating at poker (as Ashlee Simpson and the surviving member of Milli Vanilli will attest). Lip-syncing is quite simply mouthing the words of a pre-recorded song in a live-performance context while trying to create the illusion that one is actually singing. Lip-syncing was a common practice in the days of live television variety shows, such as the Ed Sullivan Show, and was in fact insisted upon in order to guarantee that the “performance” would come off as professional. Also, since there were so many acts that had to take the stage in rapid succession, not actually miking a band could prevent some serious problems. With broadcast and live sound reinforcement equipment it its infancy, the advent of loud rock bands showing up on television made for too many (possibly disastrous) variables. Keep in mind that in England during this period, if a console squealed once during a broadcast, the engineer would be fired. To prevent any sonic surprises, the BBC insisted on preamps designed with at least 30dB of headroom.