At this time , Linda G. Thompson left the group .
At this time , Linda G. Thompson was replaced by New Yorker Rhonda Heath , who was chosen over other hopefuls at an open casting call to become the newest singer for the group .
At this time , Linda G. Thompson left the group and was replaced by New Yorker Rhonda Heath , who was chosen over other hopefuls at an open casting call to become the newest singer for the group .