Quodlibet

A quodlibet is a piece of music which combines several different melodies in counterpoint, usually popular tunes, and often in a light-hearted manner. A very famous example of a quodlibet is at the end of Bach's Goldberg Variations. Another example is Galimathias Musicum, a 17 part quodlibet composed by Wolfgang Amadeus Mozart when he was about 10 years old.

More serious quodlibets can be found in the masses of Jacob Obrecht[?], which sometimes combine popular tunes[?], plainsong and original music at once.