Originally published as the fourth volume of Clavier-Ubung, its current name dates from a biography by Johann Forkel, who revealed that it was composed to alleviate the insomnia of its patron, Count Keyserling.  
The parts of this work include nine canons and, in the penultimate section, a quodlibet.  It begins and ends with an aria, "Sarabande," which is found in the 1725 notebook of the composer's wife Anna Magdalena.  Originally published as the fourth volume of Clavier-Ubung, its current name dates from a biography by Johann Forkel, who revealed that it was composed to alleviate the insomnia of its patron, Count Keyserling.  Consisting of 32 sections and famously performed in 1955 by Glenn Gould, FTP, name this 1741 harpsichord work by Johann Sebastian Bach.
The parts of this work include nine canons and, in the penultimate section, a quodlibet.  
Goldberg Variations