– lead vocal, background vocal, Hohner clavinet, drums, Moog bass Paul Anka – background vocal Syreeta Wright – background vocal Shirley Brewer – background vocal Larry "Nastyee" Latimer – background vocal "Too Shy to Say" Stevie Wonder – lead vocal, piano James Jamerson – acoustic bass Sneaky Pete Kleinow – pedal steel guitar "Boogie On Reggae Woman" Stevie Wonder – lead vocal, Fender Rhodes, piano, harmonica, drums, Moog bass Rocky Dzidzornu – congas "Creepin'" Stevie Wonder – lead vocal, background vocal, Fender Rhodes, harmonica, drums, Moog bass, T.O.N.T.O. synthesizer Minnie Riperton – background vocal "You Haven't Done Nothin" Stevie Wonder – lead vocal, Hohner clavinet, bass drum, hi-hat, cymbal Reggie McBride – electric bass The Jackson 5 – background vocals Robert Margouleff and Malcolm Cecil – synthesizers Horns, drum machine – uncredited "It Ain't No Use" Stevie Wonder – lead vocal, background vocal, Fender Rhodes, drums, Moog bass Lani Groves – background vocal Minnie Riperton – background vocal Deniece Williams – background vocal "They Won't Go When I Go" Stevie Wonder – lead vocal, background vocal, piano, T.O.N.T.O. synthesizer Bob and Malcolm - programming Moog "Bird of Beauty" Stevie Wonder – lead vocal, Fender Rhodes, Hohner clavinet, drums, percussions, Moog bass Bobbye Hall – cuíca Shirley Brewer – background vocal Lani Groves – background vocal Deniece Williams – background vocal Sérgio Mendes - Portuguese lyrics Drum machine - uncredited "Please Don't Go" Stevie Wonder – lead vocal, piano, Fender Rhodes, harmonica, handclaps, drums, hi-hat, Moog bass Michael Sembello – acoustic guitar The Persuasions – background vocal Shirley Brewer – background vocal Deniece Williams – background vocal Selected cover versions "Too Shy to Say" - recorded by Diana Ross in 1978. "Too Shy to Say" - George Michael performed the song in his Faith Tour. "Creepin'" - Recorded by Luther Vandross for The Night I Fell in Love in 1985. "They Won't Go When I Go" - recorded by George Michael for Listen Without Prejudice, Vol 1 in 1990. "Too Shy to Say" - recorded by Jody Watley for Intimacy in 1993. Released as single in the Philippines. "They Won't Go When I Go" - recorded by Kevin Max for The Blood in 2007. "They Won't Go When I Go" - recorded by Stefon Harris on the album "Urbanus" in 2009. "Boogie On Reggae Woman" - covered that same year by Jamaican reggae singer Pat Rhoden, released as a single only