The show has seen seminal performances over its history. The March 1971 "TOTP" appearance of T. Rex frontman Marc Bolan wearing glitter and satins as he performed "Hot Love" is often seen as the inception of glam rock. In the 1990s, the show's format was sold to several foreign broadcasters in the form of a franchise package, and at one point various versions of the show were shown in more than 120 countries. Editions of the programme from 1976 onwards started being repeated on BBC Four in 2011 and are aired on most Friday evenings – as of October 2020 the repeat run has reached 1990. Episodes featuring disgraced presenters and artists such as Jimmy Savile (who opened the show with its familiar slogan, 'It's Number One, it's Top of the Pops') and Gary Glitter are no longer repeated.