Garth Trinkl January 5, 1987. Garth Trinkl. Seminar on Music by Morton Subotniek and Harrison Bietwish. Tags Garth Trinkl Morton Subotniek Harrison Bietwish DATE January 5, 1987 TYPE Conversation ARTIST & COLLABORATORS Garth Trinkl, Morton Subotniek & Harrison Bietwish