How to learn music theory fast

[in-depth blog about harmony & theory]

Are you auditioning for music school, and do you need to pass the music theory test? Or maybe you’ve got another reason to learn about music theory and you are in a rush. Well, don’t worry! I’ve written this article exactly for those that want to learn the basics really fast. So this is going to be gameplan in a nutshell:

Understanding what intervals are, and how they fit in the “12-tone system”. When you know that, you can learn one simple formula to play the major scale in all 12 keys. And with the 7 modes added to your knowledge, you will know about at least 12x7=84 scales by the end of this article.

So I’m going to take you step by step through the basics of music theory in this article. But before we begin a short disclaimer: of course, I’ll try to explain music theory as quickly as possible in this article, but the reality often is that it takes time to fully comprehend everything. So don’t be discouraged if you don’t understand it during your first read.

And lastly, some advice while reading this article: play along with a keyboard, or download a simple piano app if you don’t have one. You’re not gonna get good at this stuff if you’re not applying it in some way. Of course, you might learn a lot without it, but it will help you understand and memorise everything much better with a keyboard.

Understanding the 12 tone system

What’s right in front of us are 7 white keys, and 5 black keys. The white keys are called: C, D, E, F, G, A, B. Notice that they just follow the first 7 letters of the alphabet, and when you end with B, you can start over again in a new octave (more about the meaning of that word in the next part).

So far pretty simple right? But with the black keys the names get a little bit more complicated. First, we need to know about these symbols we call: sharp (♯) and flat (♭). The sharp is added to the note if we want to move on note up (so to the right on the keyboard), and the flat is used when we want to move one note down (so to the left).

So for example the first black key on the left is called C sharp, but it can also be called D flat. It depends on which note we are thinking from. The real reason why the black keys have 2 different names is a little bit complicated, so we will come back to that later. For now, this is all we need to know about the 12-tone system.

What are intervals?

An interval is a distance between two notes. So a note by itself can never be called an interval. It’s only called an interval when two notes are being played together or right after each other.

In the picture, you can see all the names of the intervals when we are thinking from C. First, we’ve got a half step from C to C#, and we call going to D a whole step. This can give you the early impression that all white keys are whole steps, and all black keys are automatically half steps.

But what if we pick E as our reference point, and go one note to the right, now this is our half step, and the F# is our whole step. This might be tricky to comprehend at first, but you’ll eventually get the hang of it.

Here is another example: when we use A♭ as our starting point, the A is now considered a half step, and the B♭ the whole step.

By the way, all the intervals with a ♭ can also be called minor. For instance, we call the ♭2 a “minor second”, and ♭3 a minor third. But we call the #4 a “raised four”.

How to play the major scale:

There is a reason why everybody always starts with the C when they have their first piano lesson. When you play the C and go to the right all the way to the next C, something miraculous happens. You’re automatically playing the C major scale.

When we look at the numbers again we’ve got the following intervals in our C major scale:

The one
Major second
Major third
Perfect fourth
Fifth
Major sixth
Major seventh
Octave

This is the traditional way of looking at the intervals in a scale and it’s essential to your music theory learning journey. But there is a second way that I also want you to learn that is going to be really useful to you later on:

When we look at the steps we are taking when doing this we get this formula: whole - whole - half - whole - whole - whole - half.

If there is only one thing that you are learning from this article, I want it to be this formula! Read this out loud at least 10 times: “whole, whole, half, whole, whole, whole, half”.

So why is this so important? Well, now that we’ve got some sort of almost “mathematical formula”, we can now apply that to a different starting note, and thus create scale in a new key.

So if we now use G as the first note we get this scale going up. Our formula tells us that we can’t play the F, but instead, we need to play the F#, so all of the sudden we have one black key in our scale, and that is exactly the note that is making the difference.

A more difficult example is E flat:

So now you know the formula, you can try it out on all 12 different keys. A common method to learn all of the keys is through the circle of fifths. Let me explain really quick: when you pick the fifth note of the C scale, we find G. We then play the major scale there, and then we pick the fifth of that scale, and then we get D. The 5th of D is A and so forth.

cheat sheet of the sharp scales

This is a cheat sheet of all the keys that go up a fifth through the circle of fifths. Notice that they are all marked with sharps and no flats. We’ll get to those in a second.

cheat sheet of the flats

So far we’ve only gone up a fifth, but you can also do this the other way. Think about it: the C itself is of course a fifth of another note as well: the F. When we play the scale of F, we get our first flat, and thus we are going down in the other way of the circle of fifths where we will only get flats instead of sharps.

And just like that: with one formula we’ve already learned 12 scales! But hey, just wait for a second! Are you even paying attention? I’m counting 15 scales here to be exact. How is that even possible? There are only 12 keys, right? So there must be only 12 scales.

Well, notice that the C sharp scale starts on the same key as the D flat scale because they are basically the same note. This also counts for G flat and F sharp, and it’s the same with C flat and B. So if there are 7 sharp keys and 7 flat keys, plus C major, there are technically 15 scales.

But since three of them are technically “doubles”, for the sake of keeping things simple we’ll say that there are 12 scales. Now let’s expand our knowledge even more by multiplying that number by learning modes!

What are modes?

There are seven different modes that all have their own names. The easiest way to think about them is to go back to our keyboard. Take a look at the white keys: how many are there again? Yes: 7 of course. Exactly how many modes there are.

So far, we’ve only talked about the major scale (in modes called: Ionian). We’ve already established earlier that the major or ionian scale has the following intervals: the one, major second, major third, perfect fourth, fifth, major sixth, major seventh, octave.

But now, we are going to start on a different note, and still only use the white keys. What will happen? Let’s use D as an example, a major second away from the C. Now when we name the intervals when we go to the right it’s: the one, major second, minor third, perfect fourth, fifth, major sixth, minor seventh, octave.

Do you see the changes? Playing from D gives us a different formula as well: whole, half, whole, whole, whole, half, whole. Does that seem familiar to you? Well, it should, because it’s just the same formula we’ve used earlier on, except that it has shifted one to the right.

Here is a cheat-cheat of all the modes with only the white keys. So you could say, that we are constantly playing the same scale, but the only difference is the reference point from where you are starting.

modes cheat sheet

Ionian: 1 2 3 4 5 6 7
Dorian: 1 2 ♭3 4 5 6 ♭7
Phrygian: 1 ♭2 ♭3 4 5 ♭6 ♭7
Lydian: 1 2 3 #4 5 6 7
Mixolydian: 1 2 3 4 5 6 ♭7
Aeolian: 1 2 ♭3 4 5 ♭6 ♭7
Locrian: 1 ♭2 ♭3 4 ♭5 ♭6 ♭7

Applying the modes in all keys

Now here comes the tricky part, but also the mind-blowing part: you can apply the modes in every scale as well: so in theory, you know about 12x7=84 scales right now. Playing them all is really tricky in the beginning but definitely advised if you want to memorise it all.

Here are a few examples of combinations that we can make:

D Lydian: D E F# G# A B C#
E♭ aeolian: E♭ F G♭ A♭ B♭ C D♭
C dorian: C D E♭ F G A B♭
F# locrian: F# G A B C D E

Playing triads through any scale

So now that we’ve learned about all sorts of different scales, let’s talk about something different now: chords. If we go back to our simple major scale of just the white keys and play the C, then we skip the D and play the E, then we skip the following note (F) again, and press the G.

Major Triad Formula:

**One - Major 3rd - Fifth**
*Picture: David Pisnoy, Erik Reino Music*

We’ve now played the 1, the major 3rd, and the 5th. In music theory, we call this a triad. And this triad in particular is called C major (or just simply “C”).

If we move this triad all up within the scale of C major, we now get D, F, A. This chord has also the 1, the minor 3rd, and the 5th. Because this chord has a minor 3rd instead of a major 3rd, we are going to call this triad D minor (“Dm” or “D-”).

Minor Triad Formula:

**One - Minor 3rd - Fifth**
*Picture: David Pisnoy, Erik Reino Music*

So if we continue going up this way through the scale, we get the following chords: C, Dm, Em, F, G, Am, Bm(♭5). Notice the last chord: B minor flat 5. It’s the only anomaly in this sequence because of the lowered 5. Going through the steps of a scale in triads is often done in Roman numerals like this: I - ii - iii - IV - V - vi - vii.

Minor Flat 5 Triad Formula:

**One - Minor 3rd - Flat Five**
*Picture: David Pisnoy, Erik Reino Music*

You can use the capital letters for the major chords and the normal ones for the minor chords, but it can also be done like this: I - IIm - IIIm - IV - V - VIm - VIIm(♭5).

We can apply the knowledge of triads to different scales as well of course. These are the triads for A:

A major: A, C#, E
B minor: B, D, F#
C# minor: C#, E, F#
D major: D, F#, A
E major: E, G#, B
F# minor: F#, A, C#
G# minor ♭5: G#, B, C#

Adding a fourth note

If we go back to our triad of C major (C, E, G), and we skip another note (the A) and then press the next one (B). We now have a fourth note added to our C chord: C, E, G, B (the 1, major 3rd, 5th major 7th). Because of the added major 7th, the chord is now called C major 7 (“CΔ7” or “Cmaj7”).

C Major 7:

**One, Major 3rd, Fifth, Major 7th.**
*Picture: David Pisnoy, Erik Reino Music*

If we now go one note up with these four notes, we get our D minor (D, F, A) chord again with an added C note to it. The intervals here are now: the 1, minor 3rd, 5th, minor 7th. Our simple triad chord of D minor is now promoted to the D minor 7 (“Dm7” or “D-7”)

D minor 7:

**One, Minor 3rd, Fifth, Minor 7th.**
*Picture: David Pisnoy, Erik Reino Music*

So if we continue to go up in this way, we get the following chords: Cmaj7, Dm7, Em7, Fmaj7, G7, Am7, Bm7(♭5). In Roman numerals you can write them down like this: Imaj7, IIm7, IIIm7, IVmaj7, V7, VIm7, VIIm7(♭5). Notice that the fifth chord, the G7, doesn’t have the “maj” in front of the seven.

The difference between dominant chords and major 7 chords:

The G7 is called a dominant chord because it has the tendency to resolve back to the 1 chord (Cmaj7). The “7” in the G7 chord is in this case an F, and it is not a major 7th (because that would be the F#), but a minor 7th. So the G7 is a chord with a major 3rd, but a minor 7th. That’s why it is different and unique from the other major chords in the scale.

G7 Dominant:

**One, Major 3rd, Fifth, Minor 7th.**
*Picture: David Pisnoy, Erik Reino Music*

B minor 7 flat 5:

In our scale of Cmaj7, Dm7, Em7, Fmaj7, G7, Am7, Bm7(♭5), we are still dealing with that tricky last chord: the B minor 7 flat 5. It’s still just the 1, minor 3rd, and flat 5, but this time with the added minor 7th (in this case the A).

More extensions

Okay this next bit is going to be a little bit advanced, so if you are only here for just the basic stuff, you can skip to the next part about common progressions, but if you are curious about this, you can definitely gain some extra knowledge from this, and you’ll never know when it might come in handy.

If we go even further up the scale after the 7th, we come back to the 8th note, the octave (C again). Once again we are going to skip one note first, and then we stumble upon D. We call this the 9th because it has passed the octave and is an upper extension of the chord.

C Major 9

**One, Major 3rd, Fifth, Major 7th, Nine.**
*Picture: David Pisnoy, Erik Reino Music*

We now have C, E, G, B, D (1, major 3rd, 5th, major 7th, 9). And if we go up through the scale now with 5 notes we get these chords: Cmaj9, Dm9, Em(♭9), Fmaj9, G9, Am9, Bm(♭5,♭9).

D minor 9

**One, Minor 3rd, Fifth, Minor 7th, Nine.**
*Picture: David Pisnoy, Erik Reino Music*

Do you want more advanced stuff? Well let’s add ourselves the sixth note, shall we? We’ll once again skip the next note (E) and go straight to F (in upper structure language this is called “the 11th” instead of the 4th). We now have the chord Cmaj9, 11: C, E, G, B, D, F, and if you want to go even more crazy you can add a “13th” note to it like this: C, E, G, B, D, F, A.

Of course, we can again go up and down the scale with these monstrous chords, but that will be a little bit off-topic for this article. I might write something in the future in a separate article about extensions like 9ths and 13ths.

Common progressions

A great example of a common progression is the I - vi - IV - V. Let’s say that we are in C, the progression will be: C - Am - F - G. If you play every chord for 1 measure, then you can already hear a sound that should probably sound really familiar. Famous songs that use this progression are: Stand By Me (Ben E. King) or Perfect (Ed Sheeran).

A second progression that you should definitely be familiar with is the ii - V - I progression, and that one is often used in jazz.

Example of using the II-V-I in a song:

In the jazz standard “Tune-Up” by Miles Davis, you can see very clearly that the song goes from a “ii - V - I” in one key to another. The first three rows are all “ii - V - I” progressions, so this song has 3 keys that alternate.

My personal opinion

Learning music theory can be quite a challenge in the beginning. Everything seems so overwhelming, and it’s like it’s never going to end. But don’t worry. The things that you’ve just read are most of the material that you need in order to understand and analyse the theory in pop music.

My personal tip is the same that I gave you at the beginning: try learning this all with a keyboard and play everything you learn. Even if you already play a completely different instrument, still use a piano or some form of keyboard. Music theory is hard in the beginning, and the piano helps us to visualise everything that is going on.

When I was studying theory a lot when I was in music school I did the exact same thing, and I think I couldn’t have passed my exams if I didn’t put in the work to really understand all of this stuff. And then when I did my exams, the piano was just in my head, and I could play whatever scale I wanted in my head.

If you’ve followed everything I’ve said so far, and you have practiced it as well, you’ll be able to do that as well. I guarantee it.

Conclusion

So now you know what intervals are, and how they fit in the “12-tone system”, and how to play the major scale in all 12 keys. You also know how to play chords in those 12 major keys, and when you think about “the I” as a different step in the scale, you can also play in the 7 different modes. With all this knowledge, we now know how to produce 12x7=84 scales!

Rhythm (a subject for a separate article)

You might have noticed that I haven’t talked at all about rhythm, and it is for a reason because rhythm is almost an entirely different subject within music theory and deserves its own article because there is obviously so much to talk about. So stay tuned for that article!

How to learn music theory fast

How to learn music theory fast

[in-depth blog about harmony & theory]

Understanding the 12 tone system

What are intervals?

How to play the major scale:

cheat sheet of the sharp scales

cheat sheet of the flats

What are modes?

modes cheat sheet

Applying the modes in all keys

Playing triads through any scale

Adding a fourth note

The difference between dominant chords and major 7 chords:

B minor 7 flat 5:

More extensions

Common progressions

Example of using the II-V-I in a song:

My personal opinion

Conclusion

Rhythm (a subject for a separate article)

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