Born 1959 in Zurich, Käser produced his first compositions as a child, and had the feeling he could experience the world musically.
Between 1978 and 1982 he studied guitar at the 'Musikhochschule Zurich / Winterthur'. From 1983 to 1985 he studied composition under Hans-Ulrich Lehmann in Zurich and then from 1985 to 1989 under Roland Moser at the 'Musikhochschule Basel'.

Subsequent to 1990 he received his first experiences in composing and performing for theatre, he was later to become the director of his own theatre and music theatre project. Käser is the founder of various ensembles, the most recent being the improvisation trios III. VII, XII, with whom he performs as a vocalist. Mischa Käser lives as a guitar teacher, composer, director and musician in Zurich, his compositional strong points being vocal music, chamber music and musical theatre.