The piano is a great instrument because of how easy it is to pick up on it. Unlike other instruments like the violin, or the guitar, you always know what you are going to get when you attempt a note. It also sounds amazing to the ear and is very relaxing to the ear.
All of the Above. None of them did any influencing to Jazz music.
The materials he used to paint with is fading away and soon it will be completely gone if it is not repainted on a daily basis.