Complex sentence: He would sing to great acclaim at the Met until 1974 in roles such as Calaf, Cavaradossi, Maurizio, Ernani, Rodolfo, Edgardo, and also undertook French roles in new productions of "Roméo et Juliette" and "Werther".
Split into simpler sentences: He would sing to great acclaim at the Met until 1974 in roles such as Calaf, Cavaradossi, Maurizio, Ernani, Rodolfo and Edgardo. He also undertook French parts in new productions of "Roméo et Juliette" and "Werther".