If opera as biography is your bag, then Alexander von Zemlinsky’s Der Zwerg (The Dwarf) should be top of your shopping list. In 1900, Zemlinsky fell in love with the young Alma Schindler, one of his composition students. At first his feelings were reciprocated, though Alma described him in her diary as “dreadfully ugly, almost chinless.” Her friends, however, were scandalized. Alma was a statuesque, upper class nuptial prize while, at 5’1” and with no great reputation as a composer, the lowly-born Zemlinsky was way below her in every sense of the word. A “skinny dwarf” was what the local Viennese called him. When the relationship inevitably went south, in 1902 Alma married Gustav Mahler. Zemlinsky never quite forgave her, working out his feelings first in the orchestral tone poem Die Seejungfrau (The Mermaid) and then, between 1919 and 1922, in Der Zwerg, his one-act opera on Oscar Wilde’s The Birthday of the Infanta.

In the opera, the proud Infanta Donna Clara has been sent an ugly dwarf as a birthday present. At first, the princess and her maids trifle with the poor fellow who is unaware of his physical defects. The...