While the fables and sacred songs by Luther's pupil Erasmus Alberus are often quoted and sung, it has only been possible to speculate on the Gospel harmony he wrote in German, as the manuscript was regarded as lost after the Second World War. After its rediscovery, this work is now made generally available in the present edition. The edition gives a detailed explanation of the structure of the harmony and provides an expert assessment of the position of the harmony in the overall tradition of the Middle Ages and the Age of Reformation.