 " Fantasy " is an uptempo pop , contemporary R & B , and dance @-@ pop song , which blends elements of funk , hip hop , and bubblegum pop . " Fantasy " moves at a tempo of 102 beats per minute . The remix , which features rap verses from O.D.B , also incorporates hip @-@ hop into the bridge . The song uses heavy bass and percussion , as well as a sample from " Genius of Love " . The song is set in the signature common time , and is written in the key of G major . It features a basic chord progression of A ♭ -F ♭ -1 . Carey 's vocal range in the song spans from the note of D3 to the high note of F6 ; the piano and guitar pieces range from D ♭ 4 to E ♭ 5 as well . The song contains choral lyrics written by Carey , who also developed the song 's melody and original beat . Instrumentation and production was performed by Dave Hall , while co @-@ arranging and producing the track as well . The members of the Tom Tom Club , Tina Weymouth , Chris Frantz , Steven Stanley and Adrian Belew are all credited as writers due to the inclusion of the music sample they wrote . 
