The sound document as a source Can sound documents be ‘written’? and can they be ‘read’? The beginnings of the history of sound recording give useful elements to understand these processes and these terms and to clarify their peculiarities. History and music disciplines have considered the role of sound documents as sources, with different ways and in different times. A definition of sound document will be attempted based on the process of sound recording, of which an outline will be given. The document, being an object, is the result of the union of a carrier with a format. The matter of ‘decodification’ of a sound document from a technological point of view will be considered: from here the importance of the technical devices used in the process of reprodution and re-recording. In the end the central topics of originality, authenticity and integrity of sound documents will be considered, taking some examples among the music repertoires without notation: music of the oral tradition, improvised, electroacoustic, phonographic.