It is said that in a recital given on 23 March 1783 with the celebrated composer Christoph Willibald Gluck most likely in attendance, Mozart improvised variations on the song ''Unser dummer P÷bel meint'' from Gluck's Singspiel Die Pilgrime von Mekka. He later put them to paper and had them printed three years later. It is quite possibly Christoph Willibald Gluck's celebrity that was responsible for K. 455 being one of Mozart's musically most demanding variation cycles.