Musicians and intellectuals (or their heirs) who have connections with the Orfeó Català have enriched the Library’s collection with legacies and donations: Pep Ventura, Josep Anselm Clavé, Josep Ferrer, Josep Rodoreda, Apel·les Mestres, Carles Gumersind Vidiella, Antoni Nicolau, Josep Rafael Carreras i Bulbena, Joan Salvat, Amadeu Vives, Father Lluís Romeu, Juli Garreta, Vicenç Maria de Gibert, as well as Joan Llongueras i Badia, to name but a few. It has therefore become one of the main music libraries formed by a private civil organisation, and not just because of the volume of documents kept here, but rather for its heritage value. The library holds a wide range of documents (engraved, printed or handwritten scores, books, opera librettos, letters, programmes, posters, administrative documents …) and collections of popular songs.
Throughout its history, the Library has marked the entrance of documents with the seals that were also used by the Orfeó Català. Francesc Flos i Calcat’s design was used from 1895 to 1905, after which that of Adrià Gual was introduced, reflecting all of the symbolism of the Orfeó Català and the first notes of El cant de la senyera.