From October 1971 to March 1972, Callas gave a series of master classes at the Juilliard School in New York. These classes later formed the basis of Terrence McNally's 1995 play "Master Class". Callas staged a series of joint recitals in Europe in 1973 and in the U.S., South Korea, and Japan in 1974 with the tenor Giuseppe Di Stefano. Critically, this was a musical disaster owing to both performers' worn-out voices. However, the tour was an enormous popular success. Audiences thronged to hear the two performers, who had so often appeared together in their prime. Her final public performance was on November 11, 1974, in Sapporo, Japan.