Mariah Carey

—Carey on her usage of the whistle register
Mariah Carey possesses a five-octave vocal range, and has the ability to reach notes beyond the 7th octave. Referred to as the "songbird supreme" by the Guinness World Records, she was ranked first in a 2003 MTV and Blender magazine countdown of the 22 Greatest Voices in Music, as voted by fans and readers in an online poll. Carey said of the poll, "What it really means is voice of the MTV generation. Of course, it's an enormous compliment, but I don't feel that way about myself." She also placed second in Cove magazine's list of "The 100 Outstanding Pop Vocalists".
Regarding her voice type, Carey said that she is an alto, though several critics have described her as a soprano. However, within contemporary forms of music, singers are classified by the style of music they sing. There is currently no authoritative voice classification system within non-classical music. Attempts have been made to adopt classical voice type terms to other forms of singing, but they are controversial, because the development of classical voice categorizations were made with the understanding that the singer would amplify his or her voice with their natural resonators, without a microphone.
Jon Pareles of The New York Times described Carey's lower register as a "rich, husky alto" that extends to "dog-whistle high notes". Carey also possesses a "whisper register". In an interview with the singer, Ron Givens of Entertainment Weekly described it this way, "In one brief swoop, she seems to squeal and roar at the same time: whisper register." Additionally, towards the late 1990s, Carey began incorporating breathy vocals into her material. Tim Levell from the BBC News described her vocals as "sultry close-to-the-mic breathiness", while USA Today's Elysa Gardner wrote "it's impossible to deny the impact her vocal style, a florid blend of breathy riffing and resonant belting, has had on today's young pop and R&B stars."