Evidence of reworkings by Restoration composers of their own pieces is not difficult to find, but inevitably such material has survived in a haphazard fashion. Only rarely does one come across examples like Matthew Locke's scorebook of consort music, London, British Library (GB-Lbl), Add. MS 17801, where alterations have been made systematically. Even where such examples do exist, the common contemporary practices of cutting out rejected leaves or of scraping away the original notes on a page often make it impossible to analyse the revisions made: of course the composers themselves could never have imagined that anyone would be interested in their cast-offs and made no attempt to preserve them. It is something of a stroke of luck, then, that three distinct and almost complete versions of an anthem by William Turner should be extant: they allow an unusually detailed study of the revision processes of a successful Restoration composer. What emerges as most important from such a study is the fact that Turner's reworkings of each section of the piece appear to show a consistency of purpose that one simply cannot search for in the odd revised phrases and bars which survive for most other composers of the period.

Eduard Hanslick's The Beautiful in Music (1854) is a classic of musical aesthetics. Its influence has been profound, not least as a polemic against Wagner's Opera and Drama (1851). The polemic was defended by the author in his preface to the seventh edition of 1885, which contains the oft-quoted evaluation of music drama as ‘formlessness exalted into a principle’. The Hanslick/Wagner debate defines an aesthetic and theoretical ground zero around which significant forces have been arrayed. The results have been complex and mixed. While Wagner's music prevailed and his theories were generally dismissed, Hanslick's rejection of music as a medium for expressing feelings articulated an approach brought to fruition by Heinrich Schenker (who unsurprisingly shared Hanslick's negative view of Wagner as well as his polemical tendencies).

Reflecting on the composition of his First Chamber Symphony, op. 9, in the essay ‘How One Becomes Lonely’ (1937), Schoenberg wrote: