Even though they recorded their tracks separately, Marvin Gaye and Tammi Terrell released the duet "Ain't No Mountain High Enough" (Ashford - Simpson) in 1967 and hit the top twenty. This is from their album "United" featuring the Funk Brothers.
In 1968 The Supremes and The Temptations teamed for an album called ""Diana Ross & The Supremes Join The Temptations".

Diana Ross shows her vocal capabilities in 1970 with the album "Diana Ross" and reaches the top of the charts for the first time without the Supremes with her Grammy nominated effort. The Detroit Symphony Orchestra provided strong backup with composers Nick Ashford and Valerie Simpson singing included on the session.