224 artists, 4294 songs
Nirvana's rise to the top of the pop charts in the early 1990s was as surprising as Michael Jackson's dominance a decade earlier was predictable. Thanks to Billboard's adoption of the SoundScan system, which tracked record sales at major retailers, public perceptions of pop were challenged by a diverse group of heavy metal, hip-hop, country and alternative rock albums that topped the charts alongside releases from the usual pop and R&B artists. Unlikely stars like Matchbox Twenty, Hootie & the Blowfish and Alanis Morrissette sold more records in the '90s than superstars like Madonna and Prince. Meanwhile, singers like Mariah Carey and Celine Dion and manufactured sensations like Britney Spears, the Backstreet Boys and *NSYNC followed the time-tested trail to the top of the charts by concentrating on theatrical vocals and classic pop song structures.