Born in 1964 in Frankfurt-am-Main, Johannes Caspar Walter studied composition with Volker David Kirchner (1981-1982), Johannes Fritsch, and Klarenz Barlow at the Cologne Musikhochschule (1985-1990). He also attended the classes of Johannes Fritsch at the Darmstadt Summer Course.

From 1982 to 1983, he explored the mathematical foundations of music and constructed a set of percussion instruments with a tonal system comprising a 44-note octave, based on just intonation.

He cofounded Thürmchen Editions in 1985, and participated in the creation of Ensemble Thürmchen (a group dedicated to contemporary music and experimental theatre) in 1991. He remains the cellist in the ensemble.

His works have been performed in Japan (premieres of N° 1, N°2, and Vier Stücke gegen den Stillstand), USA (premiere of Farben), and at the Stockholm and Copenhagen Festivals (premiere of Dürchscheinende Etüde I/c).

Caspar Johannes Walter has received numerous composition prizes and grants, such as grants from the city of Cologne and from the region of North Rhine-Westfalia, the Irino Prix (Japan), a First Prize in the Wien Modern Competition, the Hindemith Prize at the Schleswig-Holstein Music Festival Musique, and a grant from Villa Massimo in Rome.