Two German trombonists, Matthias and Matthias Muche, extend the trombone language through four open improvisations using advanced techniques and bizarre language, each appropriately titled for phonemes, as the two players explore the strangest and most interesting sides of their instruments to the benefit of the intrepid listener.

This pioneering British group recorded these track in the 1970s, pushing free improvisation and experimental music, in their day performing alongside Henry Cow, Red Brass and Lol Coxhill.