Due to their success, the group had to leave school in order to perform and despite the promise of tutors to help with their schooling, they were never granted any. Due to their young ages and Horton being an orphaned ward of the courts, they eventually were taken in by Esther Gordy Edwards, who bused them to Motortown Revue shows. After several successful Top 40 recordings, the group released the modest success, "Strange I Know", which peaked at #49. In early 1963, the group was shortened to a quartet when Juanita Cowart opted to leave, citing a mental breakdown---caused by stress from performing on the road and a mistake she made in describing the group's background during an appearance on "American Bandstand". Carrying on as a quartet, the group issued one of Holland–Dozier–Holland's early compositions, "Locking Up My Heart", which peaked at #44. It was one of the first singles to feature Horton and Young in co-leads. The success of "Locking" was probably tested due to strong airplay by the song's B-side, the Young-led ballad "Forever", which also received a pop charting, peaking at #78. Then Berry Gordy composed and produced the single, "My Daddy Knows Best", but it was their lowest charting at the time, #67.