Fleischer was one of the greatest American musicians of the twentieth century (and a chunk of the 21st!), and his story is one of consummate musicianship along with triumph to overcome and live with disability. Fleischer was already a pianist and teacher of great renown by 1964, when a neurological condition made playing with his right hand impossible. Fleischer didn't lose a step, though: because one-armed pianists are hardly unheard of, there is a substantial amount of repertoire for them, including today's feature piece.
Maurice Ravel, the great French Impressionist composer, was commissioned by an Austrian pianist named Paul Wittgenstein to write a concerto for him. Wittgenstein had lost his right arm in World War I, however, so Ravel wrote his Concerto in D for Left Hand. It's an amazing, bravura work, with such impressive piano writing that it is never obvious that only one hand is playing.
Wittgenstein appears to have been a rather prickly individual; he clashed with Ravel about the Concerto, revising it himself before playing it, to Ravel's displeasure. Later he commissioned another Concerto for Left Hand from composer Paul Hindemith, but Wittgenstein decided he didn't like the piece, so he refused to play it--but he also owned the rights to it, so he never let anyone else play it, either...until long after his death, when Hindemith's score was found in Wittgenstein's papers. The work was finally premiered in 2004, more than 40 years after Hindemith's death. The pianist who premiered it?
In the 2000s, even though he had a long career of left-hand piano playing, conducting, and teaching, Fleischer began undergoing experimental treatments in hopes of regaining control of his right hand. These treatments proved somewhat successful, enough for him to resume two-handed piano performance. In 2007 Fleischer was a Kennedy Center Honoree, inducted by President George W. Bush.
Here is Leon Fleischer performing Ravel's Concerto for Left Hand in D Major.