Moreover , in terms of structure , Alkan in his compositions sticks to traditional musical forms , although he often took them to extremes , as he did with piano technique . The study Op. 39 , no . 8 ( the first movement of the Concerto for solo piano ) take almost half an hour in performance . Describing this " gigantic " piece , Ronald Smith comment that it convince for the same reasons as do the music of the classical masters ; " the underlying unity of its principal themes , and a key structure that is basically simple and sound . "