It is important for the student to listen to quality music at every opportunity, guitar or non-guitar, in order to build up his or her knowledge and appreciation of music. As for the guitar, I would recommend recordings (the great majority of which are only available on vinyl) of the great players Segovia, Diaz, Bream and Williams made between the 1950's and the 1980's, as this constitutes, in my opinion, the great period of playing and recording the mainstream repertoire.