The early Romantics, it is said, formulated the idea of absolute music. If this is so, then its emergence at the close of the eighteenth century was muttered rather than announced by them. In fact, the Romantics were so reticent on the subject that they did not even name absolute music ‘absolute music’; that task was left to Wagner in the 1840s. The Romantics, however, did call instrumental music ‘pure music’, and this can be read as ‘absolute’, for they used the term to imply that instrumental music, as the essence of music, is the spirit of creativity itself. Music is pure poesis, claims Tieck; it is the ‘centre and circumference of all the arts’.
But what did this ‘Romantic music’ sound like to the Romantics? By the time someone like Schumann stylized Romantic philosophy as music, it was too late. When the Schlegel brothers, Novalis, Tieck and Schelling were writing in the late 1790s, Schumann was not even a gleam in his father's eye. There was no ‘Romantic music’ as we know it, only what we call ‘Classical music’. What the Romantics heard were the symphonies of Stamitz or Haydn and they renamed the music as their own. E. T. A. Hoffmann, in his celebrated review of Beethoven's Fifth Symphony, simply appropriates Haydn and Mozart as Romantic composers in retrospect.
The idea of absolute music is therefore not ‘Classical’ but ‘Romantic’.