The Music Collection of the National and University Library also stores a set of historical sound recordings representing a rarity in the frames of Slovenia. It consists of approximately 50 old sound recordings, mostly from before the World War II. These recordings are not reproducible any more with classical gramophone equipment, and shellack from which these records are made is extremely fragile. For the purpose of protecting the records themselves and to enable listening to them it was decided to transfer the sound recordings from analogue medium to the digital one. An audio source can represent a starting point for further research of the outline of the significance of this outline of discographic production in Slovenia from the point of view of history, culture and publishing activities. On the level of basic tasks of the National and university library, performed digitization enabled revitalization and access to forgotten and technically inaccessible Slovenian artistic cultural heritage. It reveals interpreting, receptive and stylistic traits of the time which we were so far able to reconstruct only in frames from secondary sources (published reports and critiques, memories, correspondence etc.). For the understanding and study of the history of music this acoustic documentation is of unprecedented value and adds to the central role of the national library, i.e. collecting, preserving and use of important cultural heritage. The present contribution is presenting the concept and methodology of work in detail, as well as the process of the transfer from analogue to digital format, the organization of metadata: as well, it concentrates upon the experience and exposes the results, followed by the description of starting points for further plans for the digitization of music periodicals, printed music, manuscripts and correspondence.