Several years ago I was staying with a family in Germany and learned that the German musical alphabet is slightly different from the one I knew. Specifically, the note that we call B is called H in the German system, and their B is what we call B-flat. How did this come about? Given that quite a number of great composers were from German-speaking lands, you’d think this would’ve been standard. Also, why in the world did they choose H? It’d make sense if H followed G, but it doesn’t, it follows A. I’m baffled by this. Any ideas?
as with everything in music, there is a perfectly irrational explanation behind this. 
in early days (we’re talking about the 1550’s and earlier), what is now known as the major scale, was called the ionian scale. it wasn’t immensely popular. much more popular was the mixolydian scale, which is identical to ionian, but with a B-flat, instead of a B. similarly popular was aeolian, which was like today’s minor scale, but with Eb, Ab and Bb both when ascending and when descending. greensleeves would be an example of aeolian.
upon playing this song, however, you will notice that it’s not always a Bb. sometimes it’s a Bb, and sometimes a B, because the leading note (the semitone under the tonic) is needed to make a cadence.
so, while all the other tones of the scale were consistently either “straight”, flat or sharp throughout one piece, this did not apply to the seventh tone, which could be either a semitone or a whole tone under the tonic, depending on the composer’s (and perhaps on the performer’s) whim.
now, when they went to write a piece down, they frequently just wrote the letters of the notes, instead of a line system, like we are used to today (because paper was very very expensive, and the line system uses much space). since the seventh tone was the only tone that you had to indicate whether you wanted it high or low, they thought of the following:
a “high B” sounds hard, so let’s draw the letter in a hard way: make it edgy. this looked like the lower case “b”, but drawn with straight lines, and no curves. this was called the “B quadratum”.
a “low B” sound soft, so let’s draw the letter in a soft way: make it round. this looked just like the usual lower case “b”. this was called the “B rondutum”.
nooowww… because the B rondutum looked just like the letter b (which it was), people in germany went on calling the note “B”.
but the B quadratum looked way too much like the gothic lower case “h”… the rest is history. 
apparently, this misunderstanding did not occur in england. and when the time came, and people started perceiving the quadratum and the rondutum as two different notes (rather than as two states of the same note), they chose to make the quadratum the default B, because by then the major scale had already displaced the mixolydian, so the semitone under the tonic seemed more “defaulty” than the whole tone.
eventually, the quadratum evolved into the natural sign (the sign that cancels a previous alteration), while the rondutum became the flat sign.
why did this only happen in germany?
- england was too separated, and was never much influenced by german music (even händel was a german only of birth and language, while the music he composed is italian style).
- france, italy and spain eventually ditched alphabet altogether. the italians say do re mi fa sol la si, while the french say ut re mi fa sol la si.
oh my, this post doesn’t make any sense at all… i should get more sleep. 
this is what happened in england:
while this is what happened in germany:
sorry for confusing you.
Major and minor scales are still called Ionian and Aeolian these days, though the terms are not commonly used, unless you’re having a discussion about diatonic modes. (The modes taught today are actually substantially different from the original Greek ones after which they are named.)
My complements, Apollon, for your excellent explanation. I was always curious about that peculiarity.
IIRC: the notation is a corruption of the flat and sharp signs. b -> b, and, #-> H. (On preview this is what Apollon said).
Whatever, it has the advantage that you can spell out the name BACH musically. Unfortunately it’s a pretty measly theme, didn’t stop Bach using it though.
shostakowitch did that too.
D (for dmitry)
S (from Es, which is the german pronunciation of E-flat, and also the pronunciation of the letter S)
C
H (the english B)
(SCH being the german equivalent of the english SH sound)
D Eb C B sounds much better than B A C H 
it appears in several of his string quartets, and also in his 10th symphony. probably in even more works that i’m not aware of.
max reger went even further. he spelled the words AFFE (monkey) and SCHAF (sheep) musically, in a piece dedicated to his critics.
the nicest musical name was that of my counterpoint teacher, G.F. HAAS. it sounds like a theme by alban berg.
close.
the sharp (#) evolved out of the natural ([inkpen]n[/inkpen]), which evolved out of the quadratic latin lower case B, which was mistaken for a gothic lower case H ([schwaben alt]h[/schwaben alt]).
This question was raised at the site of the following link:
http://www.ibreathemusic.com/forums/showthread.php?p=40303
After a series of more or less useless contributions, there’s one by user “glbaritone” that’s a little obscure in details but seems historically and music-theoretically well informed. (The gist of it is that in medieval musical nomenclature (a) there was no conception of “accidentals”–that is, of modifying pitches by sharpening or flattening, and (b) there were two basic scale sequences, which included exactly the same pitches with one exception. The first of these sequences came to be labeled EFGABCD–glbaritone doesn’t explain why it begins with E. The alternative sequence went from E back through E, but had a different pitch in place of B, which therefore was labeled by the first letter not yet used–H. But H was a half-tone higher than B, and a half-tone lower than C–i.e., it was what most of us, in current notation, call B, while the one then called B is what most of us now call B-flat. The Germans and others who use the B and H notation simply adhered to the older usage even after flats and sharps came into use in musical writing.)