At the time of writing, for Adorno, 'The change in the function of music involves the basic conditions of the relation between art and society.' (1991: 34) On popular music forms, Adorno is scathing: 'The familiarity of the piece is a surrogate for the quality ascribed to it. To like it is almost the same thing as to recognize it. An approach in terms of value judgements has become a fiction for the person who finds himself hemmed in by standardized musical goods.' (1991: 26)

Adorno's 'On the Fetish Characer in Music and the Regression of Listening' (1991: 29-61) suggests that the score is the work of art and the music is a by-product, and suggests that the listener reassembles the score internally... 
'the essential function of conformist performance is no longer the performance of the "pure" work but the presentation of the vulgarized one with a gesture which emphatically but impotently tries to hold the vulgarization at a distance.
'Vulgarization and enchantment, hostile sisters, dwell together in the arrangements which have colonized large areas of music. ' (1991: 36). 

The score is partly a purer form more closely associated with production that affirms use value over exchange value of the performance itself in which the listener is a consumer of the commodity form of music - the commodity fetishism of music in other words.
The listener is removed, or alienated, from an engagement with the apparatus itself: 'The liquidation of the individual is the real signature of the new musical situation.' (1991: 31) Modern ways of music distribution, using this argument would be seen to be free, but on the other hand promote the sales of computer equipment. 'regressive listening is tied to production by the machinery of distribution'. (1991: 42)