and was then repeated entire; but now only the first four bars are retained, the four last are omitted, and movement and expression are provided by a shake passage. The conclusion of the first part is rendered more impressive by a new and broader motif, and more homogeneous and concentrated by the recurrence of the first subject. The working-out of the second part, which was confined to the elaboration of the two first bars of the original motif, is partially retained; but it is extended by the recurrence and elaboration of the {MOZART'S STUDIES.} (315) principal theme. Finally, a new and important climax is introduced in the coda by the opposition of the two chief subjects. This work may be taken to prove that Mozart was a severe self-critic, and was not by any means always content with his first attempts. It can only be by chance that no other example of remodelling a composition has been preserved; the earlier attempts and studies would, no doubt, be generally destroyed. The greater part of Mozart's works of this period have been preserved in carefully written fair copies. We are amazed at the vigour and ease with which he worked, but it would be wrong to represent him as able to dispense with studies and preparatory sketches, even for his great works. The creative power of genius is indeed a gift of nature, but a mastery of art is only acquired by hard labour and pains; strength to labour indefatigably and ability to make the labour bear fruit are the prerogatives of genius. It would be doing Mozart an injustice to deny him the reputation of true and conscientious industry; the beauty of perfect work proves not that no labour has been bestowed on it, but that the labour has been successful. Mozart's youth was occupied with his endeavours to master the forms and materials which he found ready to hand, and he would not be likely to neglect studies and exercises to this end, though he might not think them worth preserving. There must have been little encouragement accorded to quartet music in Salzburg:[48] after 1773, Mozart composed none until 1784, when he was in Vienna.[49] {INSTRUMENTAL MUSIC.} (316)