Robert Spano conducts members of the Atlanta Symphony Orchestra, who are now locked out for the second time in two years after failed contract negotiations. J.D. Scott/Atlanta Symphony Orchestra hide caption

itoggle caption J.D. Scott/Atlanta Symphony Orchestra

Magda Olivero performing Francis Poulenc's one-woman opera La voix humaine at San Francisco Opera in 1979. Ron Scherl/Redferns/Getty Images hide caption

itoggle caption Ron Scherl/Redferns/Getty Images

Members of the American Guild of Musical Artists and the American Federation of Musicians, two of the unions embroiled in contract negotiations with Metropolitan Opera management, rally this morning at Dante Park across from Lincoln Center. Jeff Lunden/for NPR hide caption

itoggle caption Jeff Lunden/for NPR

Austrian pianist Paul Wittgenstein (who later became an American citizen) lost an arm in World War I. He commissioned composers including Maurice Ravel to write pieces for the left hand alone. Bettmann/CORBIS hide caption

itoggle caption Bettmann/CORBIS