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  • Writer's pictureHaakon Davidsen

MUSIC THEORY part 1: The fundamentals

Updated: Sep 7, 2020

Hi, and welcome to the first post of a series, covering the basics of music theory. In this post, I will go over a few fundamental stuff, before we will look at scales, harmony, chords, and more in the future.

I want to do this series in an easy and accessible way, so you can use the concepts right away in your songs. I remember when I learned music theory during college, that I could understand some of it, but not how it is used and why we used it. My guitar teacher said, «Just play the dorian mode over these chords». Sure, but HOW should I play it, WHY should I use the scale now, how does the scale SOUND on its own. All these questions were never answered. I could understand how I could play the scale up and down on the guitar, but never how they should be used in context.

This is why many musicians skip learning music theory. It is too abstract, and many people learn it without understanding why we use theory. So let me first go over a few questions that often come up;

Why should I learn music theory:

Well, you don't have to learn theory. It is only a tool. I know many musicians that can't read music or know any theory but still make great music. But it is a really handy tool. Let's say you are writing a chord progression; What chords should I use? That is a good question, and the answer is «whatever you want!». Knowing the theory makes it easier to know what chords you can go to, not what you need to go to. It is like preparing a meal. If you know what each ingredient tastes like and how they go together, it is easier to know what you need to add.

Do I have to read music to make music?

No. Unless you write music on paper or notation software. Sheet music is just a written down language that can help other people read your music without hearing it, and see what the instrument plays. The music is not on the sheet, it is in your ears.

What scale should I use over these chords?

This is the question my guitar students ask me the most. I always reply; «How do you want your solo to sound like?». From my perspective, there are no dos and don't when it comes to improvising with scales. Do you want a bluesy sound? Play the blues scale or the mixolydian! It still works over a jazzy chord progression. It just sounds bluesy. You can play a C lydian scale over C - F - G if you want. The lydian scale just gives the solo a...lydian sound. Play a major scale over a blues progression. It will not sound very blues, but it can work anyway if that is the sound you are going for.

So let me go over a few concepts first, explaining to them before we will dive deeper into them in the future parts.


Notes are the building blocks of music, and they all have their unique pitch. In traditional western music, we use A - B - C - D - E - F - G. If you want to go further than G, you just start on A again.

A beautiful screenshot of my beautiful piano VST

We also have sharps and flats. Sharps are written with # (but they are not called hashtag), and flats are written with b. Sharps raise the pitch one semitone (C to C#) and flats lower the pitch one semitone (A to Ab). Something that can be a bit confusing is the enharmonic tones. G# and Ab are not the same not written, but they sound the same. It just depends on if you raise the pitch or lower it.


Intervals are the distance between two tones. From a C to a G is a perfect fifth. We usually refer to intervals with a number. The number represents the number of half-notes between the two notes. C to C is also an interval, even if it is just the same note. Two or more intervals played at the same time is either called harmony or chord. 

The intervals are set up like this:








And the 8th note is the octave, which is the same note as the 1st, only higher. 

The A major scale

«But the piano has 12 notes between an octave when you include the black keys?» You are 100% correct sir! We separate the intervals in minor and major.

 If you take a look at the piano, you will see that from C, you will go to C#/Db and then D. The C is the 1st, and both C#/Db and D will be a 2nd. The C#/Db is a minor second, and the D is a major second. Both the minor and major scales had a major second, but scales like the phygrian uses a minor second. What interval you will be using depends on the scale you are using. 

When we include the minor and major versions of all intervals, we will have;

1th (perfect)

2nd (minor and major)

3rs (minor and major)

4th (perfect)

5th (perfect)

6th (minor and major)

7th (minor and major) 

8th (perfect)

There are times you can alter a perfect note, like a sharp 4th. But we can worry about that later.

Key signatures

Key signatures tell you what notes are sharp or flat in a song, and what notes you normally will find in that song. You can of course use notes that are not in the key you are in. Let's say you are in a room in a house, for example, the kitchen. Then there will be a set of furniture you normally will find there, like a fridge, sink, oven and a table. This is like the notes you will normally find in one key. If there is a bathtub there, it will stick out. If you play a note that is not in the key, it will stick out. It is nothing wrong with having a bathtub in the kitchen, and it can be quite useful if you like to bath and cock at the same time. It is nothing wrong about using notes from a different key (or furniture from a different room), it will maybe just give a not-expected sound. 


Scales are a set of specific notes within an octave. I often think of them as LEGO-blocks. The major scale is (W=whole tone, H=half tone) W - W - H - W - W - W - H. The C major scale will then be C - D - E - F - G - A - B - C. If you are in A major, the scale will have exactly the same intervals between the notes, only now they will have a different name and pitch. A major is A - B - C# - D - E - F# - G# - A. The notes have the same relationship with each other, but it is just a different set of pitches. 

There are an insane amount of scales, but the most common are;








And of course minor pentatonic (looking at all the guitarists out there).

I will go deeper into each scale in future posts. 


There are a lot of chords to choose from, but the most common are major and minor. A major chord consists of a root - a major third - a fifth. A C major chord will then be C - E - G. A minor chord is a root - minor third-fifth. A Cm chord will be C - Eb - G.

C major

A minor

A major Often, major chords are described as happy, minor as described as sad. I don't think this is a very well explained, because there are a lot of degrees of sad or happy, and you can make a major chord sequence sound sad, etc. But let us not go into that now (maybe if you buy me a beer, we can discuss it)

If you play the piano, it is easy to play a major or minor chord. Just play the intervals that you need, and you are good to go. If you want to play an A minor, just play A - C - E. 

If you play the guitar, most chords are not structured like the piano. If you play the standard inversion of A minor, you will play A - E - A - C - E. This does not mean it is a different chord. It is still an A minor, just as good as any. If you play E - C - A, it is still an A minor (it can technically be other things too), just as good as your first A minor. You can structure the notes in any order you want. As long as it contains each of the specific pitches, it is an A minor. And this goes on all chords, no matter what chord you play. 

Each scale can make up a lot of different chords, that will then fit into a key signature. 

D major scale

E minor scale Conclusion

Okay, this is a pretty rough explanation of all the basics. But it covers most of it. I will go more in detail on all of these concepts later on, but I thought it could be nice to just clear out some of the basics first.

Stay tuned for the next part!

Haakon Updated 26.08.2020: Spelling errors


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