Complex sentence: Barbarin led the group until 1969, after which time Louis Cottrell, Jr. took over; after his death in 1978 Placide Adams played with ensembles under this name until near the end of the 1980s.
Split into simpler sentences: Barbarin led the group until 1969, after which time Louis Cottrell, Jr. took over. Jr. in 1978 and played with ensembles under this name until near the end of the 1980s.