The first in a set of three pieces by this composer opens with an E-flat minor theme over triplet arpeggios, followed by a restatement in the parallel major. Extremely slow interpretations of the first movement of a late piano sonata by this composer were popularized by Sviatoslav Richter, who switched from Bösendorfer to Steinway to record a fantasy by this composer that opens with thundering C major chords in a “long, short-short” rhythm. Brahms edited a set of “three piano pieces” by this composer initially intended to be a third set of four impromptus. This composer declared “the devil may play it” in reference to his challenging Wanderer Fantasy. For 10 points, name this German composer whose hundreds of Lieder (10[1])include settings of Goethe in Gretchen at the Spinning Wheel and Der Erlkönig. ■END■ (10[1]0[2])