In the August issue of Q, we counted down the finest collaborations of all time, the perfect unions of two - often unlikely - voices. Now it is over to you to choose which of our top 20 is the best.
Ain't No Mountain High Enough - Marvin Gaye & Tammy Terrell - Recorded as a solo Terrell track until Berry Gordy suggested adding Gaye's vocal a few weeks later. Little over three years later Terrell was dead.
