The initial score collection of basque – navarre composers was made through queries in libraires and archives, purchase and collaboration with creatives. Since 2000 a score legal deposit copy is collected from the Basque Country Autonomous Community.

        It is from 1978 on that begin to enter cocumentary collections, archives and individual libraries, as well as institutional collections, either in terms of donation or as cession on deposit.
        On 31st December 2002 ERESBIL has 108 funds.

        This section stores the sound records of the works created by Basque composers. At present, the initial scope has been enlarged to include the entire musical production which is edited in the Basque Country, as well as the one concerning Basque musicians. Since 2000 a sound recording legal deposit copy is collected from the Basque Country Autonomous Community.

        This section collects the principal printed sources to musical research development, with an important presence of reference works. Furthermore collects monuments and european score collections to help musicians to find and study repertory.