4. Mariah Carey
A pop diva on all accounts, Mariah Carey has a five-octave vocal range that many would love to have. Her angelic voice first came on the scene In the early 90s with hits like Always be My Baby and Fantasy. Once honored by the World Music Awards as the best-selling female pop artist of the millennium, Carey just kept on shattering records, with her U.S. number-one singles.
