Wolfgang Birtel has extended the viola repertoire by adding six viola quartets, with arrangements ranging from classical titles such as the famous Bach Air, a mazurka by Chopin, 'Salut d'amour' by Elgar to more entertaining titles: from the catchy tune of the 'Favotte' by Gossec to Martini's 'Plaisir d'amour', which is no less resistant to the ear, and finally to salon music with Noack's 'Heinzelmännchens Wachparade' - all highly entertaining, both for playing and listening.