Most styles of Western European music (which have spread almost worldwide) use seven notes called A, B, C, D, E, F and G. It is possible to spell a small number of words with these letters; for example, the spaces of the treble clef spell F-A-C-E. In fact, most styles of Western European music are built on twelve notes, five of which are called, in English, ‘sharp’ or ‘flat’. In German musical terminology, though, B refers to B flat, and B natural is called H. Thus we can spell the surname of one of the most famous Western European composers, JS Bach. German B-A-C-H is English B flat – A – C – B natural. Bach was aware of this, and used these four notes in several of his compositions. Various composers have used it since, either as the basis for a whole composition, or as a passing reference. Some draw attention to it, while others don’t.
I was recently watching a video about the Requiem by Mozart, which he was in the middle of composing when he died. Relevantly, he died after writing eight bars of the Lacrimosa movement (Full of tears will be that day When from the ashes shall arise The guilty man to be judged) (video). I suddenly noticed that right there, four of the notes in the bass part are B-A-C-H. I haven’t been able to find anything online about this (eg, searching for ‘mozart lacrimosa bach motif’) but I can’t believe that I’m the first person in 200+ years to notice this.
The next question is: did he do it deliberately, or is it a reasonable or even inevitable result of the harmony at that point? The soprano part at that point has a rising chromatic line:
It is possible to harmonise this as a series of diminished seventh chords:
but that sounds rather cartoonish.
It is also possible to use a series of V – I progressions:
or V7 – I progressions:
but the same progression three times in a row always sounds basic.
Here, B-A-C-H appears for the first time, tucked away in the alto. It is much stronger when placed in the bass, which is what Mozart does, along with tweaking the fourth chord so there’s a dominant seventh followed by a diminished seventh:
I said that Bach used these notes in several of his compositions. One of these is the final fugue of The Art of Fugue, which ends incomplete just after he introduces these notes. A note by one of his sons explains: “At the point where the composer introduces the name BACH in the countersubject to this fugue, the composer died.” So Bach and Mozart both died shortly after writing these notes. There’s no curse about those notes, though. Many other composers have lived long after writing them. Franz Liszt wrote his Fantasy and Fugue on the theme BACH in 1855 and died 31 years later in 1886.