Abstract This collection primarily contains published opera, oratorio, and musical theatre libretti, along with a few programs and Metropolitan Opera House Grand Opera Season guides. These are of particular interest in terms of their covers, publication materials, and performance information. Many of the libretti were donated by music critic Olin Downes; these contain handwritten research notes, drafts of reviews, miscellaneous programs and cast lists for the Metropolitan Opera Company. Publication dates range from 1804-1960s, and composers represented include Eugen D’Albert, Louise Aubert, J.S. Bach, L.V. Beethoven, Vincenzo Bellini, Georges Bizet, François-Adrien Boieldieu, Arrigo...