With libretti for operas, cantatas, serenatas, oratorios, dialogues, and passions, and including non-Italian works performed in translation in Italy, it is one of the most important such collections in the United States.
The Kraus Collection includes the first libretto printed in Italy, Ottavio Rinuccini's (1562-1621) La Dafne (1600), as well as his L'Euridice from the same year. These and other libretti, such as the 1749 libretto for Handel's Susanna, offer the possibility of research on language use, symbolism, and censorship, as well as the study of historical and political changes, the effects of which are reflected in the libretti.
The earliest item in the collection is the libretto by Ottavio Rinuccini for La Dafne, performed in 1598, published in Florence in 1600, and generally considered to be the first opera. Also included is the first edition of Rinuccini's L'Euridice, produced in Florence in 1600 for the marriage of Henry IV of France and Maria de' Medici, and the earliest opera for which the music survives.
Noted librettists represented in the collection in addition to Rinuccini are Apostolo Zeno, Pietro Metastasio, and Arrigo Boito. Composers include Giuseppe Verdi, Domenico Cimarosa, Giovanni Paisiello, Gaetano Donizetti, and Gioacchino Rossini.