Matthias Kosmahl

Matthias Kosmahl is a Bielefeld-based jazz double bassist and music therapist whose work brings together musical improvisation, communication, and human connection. After beginning with guitar and electric bass, he gravitated toward the double bass, which is now his main instrument. Jazz is central to his musical identity, valued for its freedom, openness, and capacity for joyful collaboration.

Kosmahl performs in several musical settings. With ma:zz, a Bielefeld jazz duo featuring guitarist Manfred Matulla, he interprets jazz, related styles, and favorite songs in a personal way. He also appears with the Choral Jazz Trio and in other projects, including inclusive music-making. His website features performance videos, recordings, and children’s songs made with his wife.

Alongside performing, Kosmahl offers music therapy in an outpatient practice for children and adults with intellectual or complex disabilities. His approach draws on sensory-based and music-based communication, somatic dialogue, and sound therapy. He also offers sound journeys and sound concerts.