Cindy Birdsong did not hear Birdsong's voice on most of The Supremes' newest singles. Except for featured backgrounds on several collaborations with The Temptations, live album tracks, and some studio LP tracks, Birdsong and fellow member Mary Wilson did not sing backing vocals on the group's later singles. Session singers The Andantes substituted for Mary and Cindy on many, although not on all, cuts in subsequent Diana Ross & the Supremes albums. Both the "Let the Sunshine In" album and the "Cream of the Crop" album include tracks on which Florence Ballard, Mary Wilson and Cindy Birdsong sing back-up, often in tandem
Singing bird box the oval opening. Then it begins to turn from side to side, to flap its wings, move its tail up and down, open and shut its beak and – in some cases – turn its head from side to side, while producing an unbroken stream of birdsong. At the end of the performance the automaton falls back into the box and the lid closes. While the bird is calling, a decorative pierced grille appears with a bird-shaped hole cut into it through which the performer rises and falls. While singing, a bird-shaped piece of grille jumps up to cover the