Complex sentence: Promoted to lead singer at live shows from 1969, Lorraine Mazzola had also used the name Reparata, and continued to do so after the group disbanded, when she formed Lady Flash as Barry Manilow's back-up group in 1975.
Split into simpler sentences: Promoted to lead singer of the group at live shows from 1969, Lorraine Mazzola had also used the name Reparata. She continued to do so after the group disbanded, calling herself Reparata Mazzola when she formed Lady Flash as Barry Manilow's back-up group in 1975.