Fascinating. I'll have to pass this along to the elephant keepers at the zoo. We recently lost one of our elephants, and the one that is left is going through an incredible grief period.
Both elephants used to "do art" but they used sidewalk chalk instead of paint. "Lucy", the remaining elephant, was not the most prolific artist, but it seems to give her something to do to take her mind off her loss. Maybe some musical instuments will be equally beneficial.