“Truly,” Beethoven remarked in 1827, “in Schubert there dwells a divine spark.” Franz Schubert himself worshiped the older composer and was a torchbearer at his funeral. In the following year, he asked for one of Beethoven’s string quartets to be played at his own sickbed, days, if not hours, before he died at the age of thirty-one. Many of Schubert’s works contain homages to Beethoven: the Fate theme of Beethoven’s Fifth Symphony is the animating motif of Schubert’s terrifying song “Der Zwerg” (The Dwarf). His “Auf dem Strom” (On the River, for voice, piano, and horn) takes up the theme...