I had a friend as a teenager who was an excellent composer and musician. I'd sit by him on the piano bench and could just watch and listen to him play practically as long as he was willing to. He sung, played the guitar, lute and drums and wrote a musical performed in Germany, which he flew to watch performed ... and he loved it so much there he stayed in Europe.
Anyway, here are a few recommendations of musicians with generally relaxing piano pieces to listen to.
Giovanni Marradi had a special piano made that's transparent so the inside is visible. His music is influenced by a lot of styles from around the world. Just For You is one of his compositions I enjoy:
This was a song that made its way around the airwaves back in the 80s
Lady Di by Richard Claydermann
Franks Mills wrote the song Music Box Dancer which was very popular around the same era but I like this one by him even better.
Peter Piper Theme by Frank Mills
And last but not least, it's definitely worth doing some searching around for music by Omar Akram. This piece is one of my favorites.
Dancing With The Wind by Omar Akram