Mariah Carey’s sixth album is full of gossamer tracks that float like its titular creature. But its name also signifies her evolution toward hip-hop, which began on 1995’s Daydream and continues on this 1997 release with the lightly strutting Puff Daddy production “Honey” and the effervescent Bone Thugs-n-Harmony collab “Breakdown.” Carey’s voice is still a force to be reckoned with, as her spellbinding cover of Prince’s romantic epic “The Beautiful Ones” shows, but Butterfly flaunts her ability to use her power strategically.