Mariah Carey is an American singer, songwriter, record producer, and actress. An influential figure in popular music, she is known for her five-octave vocal range, melismatic singing style, and signature use of the whistle register. Carey is also credited with influencing vocal styles, merging hip-hop with pop through her collaborations, popularizing remixes, and helping break down racial barriers for multiracial Americans in popular culture. Referred to as the "Songbird Supreme" by Guinness World Records, she was ranked as the fifth greatest singer of all time by Rolling Stone in 2023, and has been dubbed the "Queen of Christmas" for the enduring popularity of her Christmas music, particularly the 1994 song "All I Want for Christmas Is You", which is the best-selling holiday song by a female artist.

The whistle register is the highest register of the human voice, lying above the modal register and falsetto register. This register has a specific physiological production that is different from the other registers and is so called because the timbre of the notes that are produced from this register is similar to that of a whistle.