In the description for this video, pianist and elephant-lover Paul Barton in Thailand says:
I took my piano to the mountains of Kanchanaburi to play for some very old, injured and handicapped elephants, especially a blind elephant Plara immediately behind the piano. Elephant-lovers please rest-assured – all keys on modern pianos (such as this one) are made from synthetic plastic material and have been manufactured this way for some considerable time.
Plara arrived at breakfast time and stopped munching the juicy grass when he heard music, so, (?) perhaps he was listening …
These elephants live in peaceful natural surroundings with specialized care at 'Elephant's World' Kanchanaburi.
Music: Slow movement (2) from Beethoven's Pathétique Sonata.
(thanks, Joe Sabia)