Siedah Garrett

Siedah Garrett (born June 24, 1958) is an American songwriter and vocalist, who has written songs and performed backing vocals for many recording artists in the music industry, such as Michael Jackson, Brand New Heavies, Quincy Jones, Tevin Campbell, Donna Summer, Madonna, Jennifer Hudson among others. Garrett has been nominated for two Academy Awards for Best Original Song, and has won the Grammy Award for Best Song Written for Visual Media at the 50th Grammy Awards for co-writing "Love You I Do" (performed by Jennifer Hudson) for the 2006 musical film, Dreamgirls.

source: Wikipedia