"She was the lead voice on 'Don’t Mess With Bill' and other songs written by Smokey Robinson, who said she 'had this little voice that was sexy to me.'"

From the NYT obituary for Wanda Young, who has died at the age of 78.

Among the other Robinson songs that featured Ms. Young’s voice were “I’ll Keep Holding On,” a 1965 release that peaked at No. 34 on the Billboard chart; “The Hunter Gets Captured by the Game,” which rose to No. 13 in 1967; and “My Baby Must Be a Magician,” which hit No. 17 in 1968.

Here's the History of Rock Music in 500 Songs episode about The Marvellettes:

After a couple of flop follow-ups to “Too Many Fish in the Sea”, Smokey Robinson took over their production, and decided to start using Wanda as the lead vocalist, rather than Gladys [Horton], who had sung lead on their hits up to that point. “Don’t Mess With Bill”, their first single of 1966, became their first top ten pop hit since “Playboy” in early 1962....

Robinson also wrote the marvellous “The Hunter Gets Captured by the Game” for the group... Or, at least, he wrote it for Wanda. By this point, while the records were getting released as by “the Marvelettes”, Robinson was only using Wanda for lead vocals, and having the Andantes sing all the backing vocals. The explanation for this was generally that the group were on tour all the time, and it was easier to make the records without them and then get Wanda just to sing the lead, and the other members reluctantly accepted that, but it rankled....