So apparently composer and pianist Michaël Levinas who studied music together with people like Gérard Grisey and Tristan Murail and participated in projects such as Ensemble l’Itinéraire is the son of Emmanuel Levinas. I have never heard any of his recordings, but judging by his affiliations, I’d say it’s probably something “spectral”…
In related news, Boethius wrote an influential (and unfinished) book on music theory – De institutione musica libri quinque – that became controversial during the time of “tuning wars” since it apparently defended Pythagorus’ theories (as it should have since it was long before the debates).
Marin Mersenne, a friend of Descartes who assisted in dissemination of the first draft of Meditations and collected the resulting Objections, later wrote a huge two-volume work on musical theory and everything music-related (including such oddities as organs with 19 keys per an octave) called Harmonie universelle, contenant la théorie et la pratique de la musique.
I’m still looking for an awesome story or two about someone like Leibniz penning a sonata or two. Or someone like Kant expressing an opinion (a positive opinion) on anything music-related.