Complex sentence: The membership of the Trio (Toth, Rejto, Baller) continued until Baller's retirement in 1971, when pianist William Corbett Jones joined the Trio until it disbanded in 1976.
Split into simpler sentences: The membership of the Trio (Toth, Rejto, Baller) continued until Baller's retirement in 1971. Pianist William Corbett Jones joined the Trio until it disbanded in 1976.