ドナウエッシンゲン音楽祭
Since the early 1980s he has been working as a freelance composer and author of self-published writings, as well as teaching classes at different universities on New Music, mediaeval music, history of Byzantine music as well as music philosophy. His first major presentation in concert was in East Berlin in 1986, receiving positive reviews as well as a first official publishing deal for his string quartet's score in print. In 1988 a work by Ullmann saw its first performance in West Germany when Gruppe Neue Musik Hanns Eisler guested at the Donaueschingen Festival.