Variations on an Original Theme for Orchestra (Enigma), Op. 36
The story goes that, after a long and tiring day of teaching, Sir Edward Elgar sat down at the piano and began to noodle. A little tune caught the ear of his wife, Alice, who asked that he repeat it. And so he did, throwing in variations as he went along. And so began one of Elgar's most beloved works, the Enigma Variations, with the deeply moving Nimrod variation as the centerpiece. Each movement is a variation on an unstated theme, created as a portrait of the Elgars' nearest and dearest friends, including themselves. The piece gave listeners two mysteries: who each movement described, and what that unplayed theme might be. Over time, the musical portraits have been decyphered, but that theme remains one of classical music's biggest mysteries. It's even been suggested that the theme isn't musical--it's perhaps literary or symbolic. But Elgar himself never unveiled the mystery, taking it to his grave.