Desc: Schubert en vrac: Directed by Bruno Monsaingeon. With Dietrich Fischer-Dieskau. The Mastersinger: Lesson IV (Schubert en vrac) is the previously unreleased fourth part in the TV series Dietrich Fischer-Dieskau, le maître chanteur (1992), filmed at the Hochschule der Künste, Berlin, in 1992, with Dietrich Fischer-Dieskau.