For 10 points, name this composer of a String Octet and the Reformation Symphony.
In his String Quartet No. 2 in A minor, this composer used his own song "Ist es wahr?" (IST us VARR) as a cyclic motif. The scherzo of Brahms's Piano Sonata No. 3 quotes this composer's Piano Trio No. 2 in C minor, whose own finale quotes "Old Hundredth." In Elgar's 13th Enigma Variation, *** (triple asterisk), a soft timpani roll plays while a clarinet quotes this composer's overture Calm Sea and Prosperous Voyage. This composer quoted "And he shall reign forever" from Messiah in the fast 8-part fugue of an E-flat major chamber piece written at 16. The finale of his Fifth Symphony opens with a flute quoting Luther's hymn "Ein feste Burg," while its first movement uses the "Dresden Amen." For 10 points, name this composer of a String Octet and the Reformation Symphony.
In his String Quartet No. 2 in A minor, this composer used his own song "Ist es wahr?"
Felix Mendelssohn &lt;Lifshitz&gt;