What is "bach motif"

n. (context music English) A sequence of four notes (B flat, A, C, B natural), included in a piece of music as a homage to http://en.wikipedia.org/wiki/Johann%20Sebastian%20Bach.

In music, the BACH motif is the motif, a succession of notes important or characteristic to a piece, B flat, A, C, B natural. In German musical nomenclature, in which the note B natural is written as H and the B flat as B, it forms Johann Sebastian Bach's family name. One of the most frequently occurring examples of a musical cryptogram, the motif has been used by countless composers, especially after the Bach Revival in the first half of the 19th century.