Diana Ross had only one hit in the charts.
Diana Ross . By 1975 , the Mahogany soundtrack included her third number-one hit , `` Theme from Mahogany ( Do You Know Where You 're Going To ) '' . After leaving Motown , Ross achieved her sixth and final US number-one Pop hit , with the duet `` Endless Love '' , composed for the Brooke Shields film of the same name , by and performed with former Commodores front man , Lionel Richie .