(N.b. This is still a draft and may get revised. I’m publishing it to get feedback. If you see anything egregiously wrong, as opposed to just casually wrong, please let me know!)

(EDIT 2022-12-21): Our Lord And Savior Adam Neely just put up a video that goes into more detail about what this post is about. If you’re a little more intermediate in your musical journey you may find this video a little more tasty than this blog post. If you watch the video and are still confused, maybe come back and read this article and then watch it again.

I got into a discussion on Reddit last week month which was about why Ableton was displaying the note “E♯” when (according to the person asking) “E♯ doesn’t exist”. Between my shorter answer and their follow up questions, I basically wrote what I thought would be a nice blog post that will explain some basic Western tonal music theory in a way that can gently lead into more intermediate levels of tonal theory.

I’m going to try to make this approachable to someone who knows very little about music so I will start from the ground up, and be generously linking Wikipedia and other articles if I touch on something that you might be interested in but I don’t dive into. I’m even going to put a table of contents in because I think by the time I’m done, this will be one of the longest blog posts I’ve ever written.

Because of this approach, in addition to simple errors I will make normally, there will be over-simplifications and I will flat out say some things that are wrong, but not dreadfully so. The things I deliberately say wrong will be close enough to right to not really matter for our purposes here, and I will also attempt to identify these over-simplifications.

1. Twelve Notes…
2. …Seven Letters
   1. Twelve Tone Equal Temperament
   2. So Why Do We Care about B♯?
   3. Diatonic Scale Example: The Minor Scale
3. Conclusion
4. Footnotes

Twelve Notes…

Western tonal music relies on twelve notes (the chromatic scale) that repeat every octave. This is most apparent when you look at a piano keyboard:

You see a repeating pattern of two then three black keys nestled between the white keys. This pattern then repeats. 7 white keys, 5 black keys for a total of 12 notes. When you loop around the same note has the same note value but is one octave higher. Connecting this to sound, this has the property that the frequency of the lower note is exactly half of the higher note. Octaves are therefore a 2:1 ratio when you look at their waveforms and while the human ear can certainly distinguish low pitches from high pitches, we tend to hear a “sameness” in octaves because of this ratio. This is very roughly analogous to color in the sense of vision. We can see a dark blue, or a light blue, but we will generally agree that both colors are “blue”. If time permits, I’ll get into why we hear this as a sameness a little more later on. (EDIT: It didn’t, so another time!)

In the modern era, we use the letters A-B-C-D-E-F-G¹ to represent the notes on the white keys and then the black notes are represented with these letters then appending a ♭ (for flat) to indicate one key immediately to the left (lower) of the named note (two keys with no keys, black or white, between them is called a half-step, which is the term I will use for this starting now), and appending a ♯ (for sharp) to represent the half-step up to a higher pitch.

A careful observer will note that there is NOT a black key between two sets of notes: B-C, and E-F. But remember what I said about sharps and flats? They just change the note by a half-step in the indicated direction. So C♭? E#? Isn’t that just B and F? Well, yes, but no, actually.

…Seven Letters

“Care to explain that, IG?” Why, yes, I do! Thanks for asking! Let’s introduce a few other concepts briefly before I answer that question. “Yes, but no” is only sort of accurate, and also not accurate at all.

Twelve Tone Equal Temperament

(You are not expected to understand this)

The vast majority of Western music (especially in the last 2-3 centuries) uses what is called the Twelve Tone Equal Temperament system, which I will call 12-TET from now on. I do not want to get into the deep weeds here, because temperament and tuning is a ridiculously complicated topic developed over centuries of music evolution and music theory and talking about it in any depth at this point will just confuse beginners. All we need to know is that this is a specific tuning system, the most generally familiar to Western ears, and it has some useful properties that make it broadly useful in many musical traditions, but also represent tradeoffs and compromises with other tuning systems that have their own advantages and disadvantages. Also, it is less than optimal for working with many tonal systems that did not originate from the Central and Western European music traditions.

Unless I call it out otherwise, everything I will discuss will be in the context of 12-TET and its applicability to systems beyond it is not assured. In 12-TET, indeed, there is no audible difference between B♯ and C, C♭ and B, and E♯ and F, F♭ and E. This is not necessarily true in other tuning systems. So, in this (sort of) narrow context, yes, they are the same.

So Why Do We Care about B♯?

Within this modern Western system, much (and prior to the introduction of jazz, blues, bluegrass, rock, R&B, and modern pop, almost all) was based on what are called diatonic scales. Without getting too technical, diatonic scales are scales of seven notes within an octave.² Notice that we use seven letters for note names. This is not a coincidence.

Let’s talk about notation, now. Western notation is made up of staff lines (almost universally 5) and notes are places on or between them to represent the pitches of the notes:

So the letter of each note is represented by its position on the staff. The clef, that first symbol on the left, tells the musician where the lines are set. This particular one is called a G-clef or the treble clef, partly because it looks like a stylized G, which is intentional. If you look where the center “swirly part” is centered, it is on the second line from the bottom. Notice that the G note marked is also on this second line. That is not a coincidence. This particular clef indicates where on the lines the G note above middle C is located, and it is the most common clef you will see in music notation (followed closely by the bass clef, or F-clef, which identifies where the F BELOW middle C is located, and is almost universally centered on the second line from the top). Clefs are technically movable, but this is rarely seen in modern notation. If a note is a little too high or to low to actually be ON the five provided lines, we use something called ledger lines above or below the main staff to indicate the distance. You can see that example on the first three notes in the example.

Written music, like computer code, is READ by humans much more often than WRITTEN by humans and its purpose is to convey the intent of the composer/arranger to the musician to inform the performance. So writing for clarity makes performance easier. Before we talk about the performance aspect, we need to dive into a little more theory.

Diatonic Scale Example: The Minor Scale

So let’s consider an example. One of those diatonic scales I mentioned is called the natural minor scale³. Without getting into too much about what that means, let’s just describe what that is. You start with the root note (any of the twelve) and then you count a step (2 keys up), a half-step (1 key up), a step (2), a step (2), a half-step (1), a step (2), and then one more step (2, so 2+1+2+2+1+2+2=12) that brings you back to the same note you started on, just an octave higher.

Let’s pick a super easy example and start on A and build the minor scale from there. Start on A, count 2 keys, B, then 1 key is C, then 2 keys is D, 2 more keys E, 1 key is F, 2 keys to G and then 2 keys back to A. Hey look, you now know how to play the A minor scale on a piano! Congratulations! Also, it’s easy because we don’t even have to think about when any of those little black keys come into play.

Incidentally, written out, it looks just like our example above.

Now, let’s complicate our example a little, and change the start from A to E. So from E, we go a step up to F♯, then a half step to G, a step to A, a step to B, a half step to C, a step to D, and then a step back to E.

This is how that looks in notation:

Now we have one pesky little key to deal with, but that’s not too bad. But if we have music where we’re playing that F♯ a lot, you can imagine that might get a little cluttered looking. Fortunately, music notation gives us another tool to more directly express the key, which is called the key signature.

The key signature basically sets the default sharps (and flats) used by the music, and you can override individual notes at any time by just putting a sharp or flat sign in front of the note, like in the first example. These are called accidentals. Note that accidentals once used carry until the end of the measure unless another accidental comes (or key signature, but let’s not worry about that right now) to replace it. And yes, you can cancel a sharp or flat accidental with what is known as the natural, ♮:

This example means to play E, then the F natural, then the F#. So the E white key, the F white key next to it, and then the F♯ on the black key a half step from there.

Now let’s take our convoluted example, A# minor. Start on A#, up a step to…C? No, we call that B# in this context. Remember when I said you had to use all seven letters in order? This is that. Now a half-step: C#, then a step to D#, another step to E#, a half step to F#, a full step to G# and one more full step to bring us back to A#.

The reason why every letter should be used is two-fold: 1. It allows the contour of the notes to more properly show the change in pitch, and 2. More importantly, it keeps the notation cleaner. Say for example, I’ve got a busy riff in 16th notes that just bounces back between the second and third notes of the scale. If we wrote it the way we should, this example busy riff looks like:

And now here’s the riff written with just C and C#:

Both of these examples would play essentially the same⁴. I think you’ll agree that the first example is easier to read than the second. I tell you at the beginning that every note is a half step up, so B# and C# both are already indicated, and the shape of the note contour communicates some of the pitch information. Note that I also removed the key signature, which also reduces the information to the musician. You now don’t know your key, either. If I were to add the key signature this would even complicate this further, since the first note is C natural (B#), I would have to lead off with a natural accidental.

Conclusion

I hope this article has helped to explain to you some of the reasons why in music we have different names for what appear to be the same note. In a future article, I will try to explain why this article is wrong. Remember when I talked briefly about 12-TET? Well, we didn’t ALWAYS make music like this, and 12-TET is a relatively late innovation in the history of music, and there’s all sorts of drama around other tuning systems. Sorcery! Geometric mysticism! Love stories! (I might be exaggerating a little).

Footnotes

1. Some in Central and Eastern Europe and Scandinavia use A-H-C-D-E-F-G and B for B♭ for reasons.
2. A diatonic scale is a scale with 5 steps and 2 half-steps, and the two half-steps are additionally separated by two or three steps. And it’s more complicated than that.
3. No, there is no such thing as an unnatural minor or artificial minor scale. There is, however, a melodic minor scale, and a harmonic minor scale. Additionally, the melodic minor scale has an ascending and a descending version. And in jazz, only the ascending form is considered the melodic minor scale. And the descending melodic minor scale has the same intervals as the natural minor scale. Are you confused yet?
4. While the notes are the same, to a seasoned musician you are actually conveying a subtle difference in meaning, but that’s a story for a different time.