For 10 points, name this German composer of songs such as "The Erl-King," as well as the Unfinished Symphony.
The seventeenth song in one of this composer's song cycles constantly shifts from the key of B major to B minor and back, and describes how the singer despises the color green. That song cycle by this composer also describes that singer's bitterness at a hunter for attracting his beloved, and ends with a song depicting "The Brook's Lullaby." This composer set poems by Wilhelm Müller in his song cycle Die (*) schöne Müllerin, and wrote a song accompanied by continuous rapid octave triplets in the piano, which begins with the line "Who rides so late in the dark and the wind." That song by this composer includes the fearful refrain "My father, my father," and describes the death of a child attacked by a supernatural being. For 10 points, name this German composer of songs such as "The Erl-King," as well as the Unfinished Symphony.
The seventeenth song in one of this composer's song cycles constantly shifts from the key of B major to B minor and back, and describes how the singer despises the color green.
Franz {Schubert}