"Orgelbüchlein" (Little Book for the Organ)
The Orgelbüchlein title page says "..wherein the
beginner may learn to perform every kind of choral,
and acquire skill in the use of the pedal...The book
is incomplete, containing only 46 of the planned 164
choral preludes.
He composed a few organ works in later years at Leipzig,
but for the most part his organ composition ended when
he left Weimar.