Sudip Bose at The American Scholar:
No composer exerted a greater influence on the music that came after him than Johann Sebastian Bach, who was born on this date in 1685. As we celebrate his birthday, let us consider one distinctive way in which composers have paid homage to the master: by using Bach’s name itself as a musical motif. In German nomenclature, the note (and key of) B flat is represented by the letter B; B natural is represented by the letter H. A and C are just as they are, so to spell out Bach’s surname in musical form yields a four-note motif consisting of B flat, A, C, and B. Bach himself used the motif (a kind of autograph stamp, sometimes surreptitious, sometimes not), and many others followed his lead: Robert Schumann, Franz Liszt, Max Reger, Arnold Schoenberg, Francis Poulenc, Anton Webern, Arvo Pärt, Krzysztof Penderecki, and Alfred Schnittke among them. One of the most imaginative uses of the motif came from a composer who is too often overlooked by music critics but who happened to be one of the most innovative and arresting voices in 20th-century music, Bruno Maderna.
more here.