Complex sentence: Reparata stopped performing live with the group in 1969 to pursue a teaching career and release occasional solo singles, while Reparata and the Delrons continued until 1973 with a new lead singer Lorraine Mazzola.
Split into simpler sentences: Reparata stopped performing live with the group in 1969 to pursue a teaching career but continued to release occasional solo singles. Meanwhile, Reparata and the Delrons continued as a live act until 1973 with a new lead singer Lorraine Mazzola.