The artist who created this unique and delightful sento Shinro Ohtake (大竹伸朗), must have known I was coming, because just as I entered the hot water, Fripp & Eno‘s 1975 ambient album Evening Star began to play. It was impossible for me to leave without listening to the entire 45 minute album. Needless to say, I had a good long soak.
You can listen to track 2, on YouTube. Try it in the bath.