In one of the last rehearsals before the big day, Babyface, joined by Stevie Wonder, led his band of musicians, a 32 piece string section, and a 24 person choir, in performing "How Come, How Long", which is nominated for Best Pop Collaboration with Vocals. The wall-to-wall musicians included guitarists, a bassist, an organist, a pianist, drums and percussion. The choir appears toward the end of the song thanks to the special elevator lift at Radio City. The packed stage rang with rhythm as both Wonder and Babyface traded vocal licks back and forth with Wonder climaxing the tune, showing off his vocal range. His traditional sounding and familiar harmonica added an abundance of flavor to the already beautifully written song. Babyface, nominated for seven Grammy's including Album of the Year, effortlessly ran through several takes of "How Come, How Long," with the performance getting tighter and tighter with each. In fact, each time Wonder and Babyface ended the song, those lucky enough to be in attendance at the rehearsal screamed louder. Wonder's command of the stage, along with Babyface's smooth soulful style, made for an unbeatable combination. Wonder and Babyface's performance will be one of the largest production numbers at this year's 40th Annual Grammy Awards - Scott Rubin