What do Beethoven and the children's song Fuchs Du hast die Gans gestohlen have in common? Nothing, strictly speaking. Although the song was written as early as 1824 (and theoretically, Beethoven could have known it), it has not left deep marks on his oeuvre. But what if he had known it? Wolfgang Birtel pursued this question and, in reply to it, conceived a symphony for string quartet: behind each movement is an original symphony by Beethoven (spiced with quotes from other works). The children's...