Why are notes named the way they are?

Question

In 12 tone equal temperament, why are the notes named:

C, C#, D, D#, E, F, F#, G, G#, A, A#, B

instead of, for example,

A, A#, B, B#, C, C#, D, D#, E, E#, F, F#

or any other thing?

Answer 1

I feel like I've already at least partly answered this question here. But I'll endeavor to add more here.

First of all, you aren't quite right in your description of the note-naming system. There are seven letters, and every one of these can be sharped or flatted:

• A♭, A, A♯
• B♭, B, B♯
• C♭, C, C♯
• D♭, D, D♯
• E♭, E, E♯
• F♭, F, F♯
• G♭, G, G♯

It's just that many of these end up being multiple names for the same pitch (at least in 12TET), thus they are called 'enharmonic'. There are also double sharps and double flats, but let's not go there...

The key point is that Western music, both classical and pop styles, is almost entirely tonal (or modal), and these systems are actually based on a 7-note (diatonic) scale, not a 12-note scale. The system of using letters to identify pitches dates at least to the 6th century (Boethius). Repeating the same 7 letters each octave came a few centuries later (by the 11th c., and Guido of Arezzo). Sharps and flats were added latter to introduce alterations to these notes, but these shouldn't be seen as new notes, so much as replacements for existing notes, still leaving you with a 7-note scale. All of this long predates 12TET, which, initially, was developed as a system of tuning keyboard instruments. (One alternative possibility that never caught on: a keyboard with 36 notes per octave).

The first note that people tried adjusting was B, which formed a dissonant interval of a 'tritone' with F. There came to be two forms of the letter b, written in different styles -- a rounded, or 'soft' b that meant to use the lower form of the note, and a square-ish, or 'hard' b that meant to use the higher form of the note. As these symbols became more widely used, the rounded b eventually evolved into a flat symbol, and the square b eventually evolved into both the natural symbol and the sharp symbol.

Because of the shape of the diatonic scale (consisting of whole steps and half steps: WWHWWWH), many of these altered notes ended up being the same as (or close enough to) other notes, so that you got multiple names referring to the same pitches, in different contexts.

BTW, with the advent of atonal music, some music theorists decided they didn't like this naming system based on the 7-note diatonic scale, and decided to invent a new system, called Pitch Class, in which each pitch in an octave, starting from C, is given a unique number, from 0 to 11.

Answer 2

The "base names", i.e. the letters, are much older than 12-edo. Music used to be played in just one diatonic scale (derived e.g. from Pythagorean/Ptolemaean tuning), and only when switching to another key you'd adjust some of the scale steps by way of an accidental. The order of accidentals you need to introduce is dictated by the circle of fifths.

This by itself does in no way imply there should be 12 steps – it just so happens that the third of the ♭-tones (a♭) comes out with almost the same frequency as the third of the ♯-tones (g♯); if you pretend they are the same and extend the system accordingly this gives you the number 12.

Answer 3

Why are the notes named what they are "instead of something else?"

All note-naming schemes are ultimately arbitrary. There are, in fact, many other systems for naming notes. For example, a good portion of Europeans use H for B and B for B♭ whereas, in other parts of Europe, the notes are named Do Re Me Fa Sol La and Ti (or Si). Sa Re Ga Ma Pa Dha and Ni are the note names in Indian music. All these systems evolved over centuries.

Any new and potentially more logical system of notation would be equally arbitrary. For example, MIDI, which was developed in the early 1980s, uses 128 different note "names", which are really bit strings and can be represented by numbers. Middle C, for example, equates to binary 111100 or decimal 60.

You asserted, "it would be possible to include [systems] where all symbols are letters or that the extra 5 notes without letters are after B." That's true. You could devise a system where the notes would be:

• A (same as C)
• B (same as C♯ / D♭)
• C (same as D)
• D (same as D♯ / E♭)
• E (same as E)
• F (same as F)
• G (same as F♯ / G♭)
• H (same as G)
• I (same as G♯ / A♭)
• J (same as A)
• K (same as A♯ / B♭)
• L (same as B)

This may have some advantages (and a new set of disadvantages), but you can't expect it to replace the existing systems any time soon.

Answer 4

The simple answer is that the notes were named using a minor, not major, tonality. The relative minor of C Major is A minor, ABCDEFG.