Pianist Maria Joao Pires has a moment of doubt.

(Photo: YouTube)

This video made the rounds on our Facebook page a while back. I've returned to it more than once. Astonishing is too small a word.

It opens with conductor Riccardo Chailly explaining why he programmed Mozart and Mahler in concert. Cut to the performance with the Amsterdam Concertgebouw.

The moment pianist Maria Joao Pires appears on camera, you know something is terribly wrong. The orchestra has begun and she realizes this is not the concerto she is prepared to play.

Watch how the maestro smiles and encourages her to attempt it anyway. What follows is a world class musician going through the five stages of grief -- denial, anger, bargaining, depression and acceptance -- in about 60 seconds. In front of a live audience.

Pianist Maria Joao Pires takes the stage expecting to play one Mozart concerto, but the conductor and orchestra launch into a different Mozart piece. See what happens next.

Remarkably, from memory, she pulls it off without missing a note. I've never seen anything quite like it. Inspirational. 

Richard Ray hosts from 6 to 10 a.m. weekdays on CPR Classical.