Who are some famous philosophers who also composed music?
In addition to Nietzsche:
Gabriel Marcel according to Brendan Sweetman composed music:
He also developed a keen interest in classical music and composed a number of pieces.
However, I could not find a list of these compositions.
Thanks to @sand1 from comments: "La Biblitheque Nationale Francaise list has a section for him as Compositeur(54) data.bnf.fr/fr/11914394/gabriel_marcel"
Sweetman, B. "Gabriel Marcel". Retrieved April 23, 2019 from Britannica https://www.britannica.com/biography/Gabriel-Honore-Marcel