A good question. After It's Growing the Tempts requested that they didn't have any additional voices on their recordings. The Tops seemed also to record ensemble, with Levi also singing backing parts, although they always worked with the Andantes. There's the story of Levi coming in off a plane, putting his bag down, recording a vocal, picking up his bag and getting on another plane. I guess the rest of the song was already done, including the backing vocals.

The Andantes weren't the only studio singers. The Originals sang backup, as did the Spinners, and everyone helped each other out as needed.

The Supremes were constantly touring in the sixties, with a string of hits and a lot of glitzy venue and TV bookings. It's likely that even the Tempts, the Tops and Vandellas spent more time around Detroit.