Complex sentence: Amongst the many notable members of the "Coro de la Universidad de Puerto Rico" were Justino Diaz, José Freire, Norman Veve, Paco O'Neill, Guiso Cosme, Carmencita Collazo, Sonia Cordero, and Lysette Alvarez.
Split into simpler sentences: Amongst the many notable members of the "Coro de la Universidad de Puerto Rico" was Justino Diaz. Diaz participated alongside José Freire, Norman Veve, Paco O'Neill, Guiso Cosme, Carmencita Collazo, Sonia Cordero, and Lysette Alvarez.