Music Theory

Introduction To Music Theory

This Section is an introduction to the general rules that are the basis for music in much of the world. While many people devote their lives and careers to music theory and millions of pages have been written about the subject, this will only give you what you need to understand the fundamentals.

The Notes Of Music

There are only 12 different notes that make up the building blocks of any song you have ever heard in western music. Even some music from cultures that were previously considered to have a separate music systems have been studied and found to use the 12 note system. These 12 notes create what is known as a chromatic scale and, apart from bending strings, these are really your only options to hit on the mandolin.

C, C# (Db), D, D# (Eb), E, F, F# (Gb), G, G# (Ab), A, A# (Bb), and B.

It is important to note that the “#” symbol is pronounced “sharp” and the “b” symbol is pronounced “flat”. For example, D# is the note above D and the note below E. Eb is the same note as D# simply with a different name. Each of these notes are (effectively) the same distance apart from one to the next. In reality, D# is 6% higher than D and E is 6% higher than D# and so on. These numbers are not exact, as they have been altered so that the octaves match up. The distance between two notes that are one fret apart is called a half step or a semitone, the distance between two notes that are two frets apart is called a whole step or a tone. I prefer to use the terms half step (H) and whole step (W)

An octave is a note that sounds the same as another note but twice as high. Once you go through the chromatic scale starting, for example, on G, you have the following scale. G, Ab, A, Bb, B, C, C#, D, Eb, E, F, F#… But then what? Well, you get G again, but twice as high as the G you started on. The distance between these two notes is called an octave.


If you play all twelve of these notes on the mandolin in succession, it won’t sound like much. That’s because the song we have heard all our lives have not included all twelve notes and our brains don’t like to hear it. Our brains have become accustomed to other scales. Most of the scales we hear in music from the past and present usually only have 7 different notes, sometimes only 5. The first note of a scale is called the root. The major scale, which is usually described as “happy” is played:

Root, W, W, H, W, W, W, H, Octave

While the most common minor scale, which is usually describes as “sad” is played:

Root, W, H, W, W, H, W, W, Octave

The C scale is unique in the sense that when you play the C major scale, there are no sharps or flats, just C, D, E, F, G, A, B, C. Likewise, the A minor scale has no sharps or flats. Because of this, A minor is known as the relative minor of C. In the case of G major and E minor, they both have one sharp (F#), Making E minor the relative minor of G major.


In music, an interval is the distance between two notes. We can count simple intervals by simply starting with the root and counting up to the note in question through the scale of the root. For example, the interval between a C and an A would be calculated in the following manner:

C (1), D (2), E (3), F (4), G (5), A (6)

So now we know that the interval from C to A is a 6th. However, musicians like to make things complicated, so there is more to the question. The way to calculate the more precise interval is to follow this table (don’t worry, you will learn to know the names of the most common ones very soon).

Distance in half steps Interval Name
0 Unison
1 Minor Second
2 Major Second
3 Minor Third
4 Major Third
5 Perfect Fourth
6 Tritone
7 Perfect Fifth
8 Minor Sixth
9 Major Sixth
10 Minor Seventh
11 Major Seventh
12 Octave

So now we can count chromatically, saying C (0), C# (1), D (2), Eb (3), E (4), F (5), F# (6), G (7), Ab (8), A (9). That’s a 9 half step difference, making it a Major Sixth. While it may seem like a lot now, it’s not too bad once you get the hang of it.


The Circle Of Fifths

Possibly the most important structure in music theory, the circle of fifths ties all of the notes, chords, and scales together by relating them to one another.

Again, this is a lot of information all at once, so don’t feel like you need to learn it all at once. Looking at this larger circular jumble of information, it is best to break it down into sections.

The first thing to notice is that, when you follow the outermost letters clockwise, they are all separated by perfect fifths, C to G, G to D, etc. Following the circle counterclockwise, the progression moves in fourths, C to F, F to Bb, etc.

As a practical tool, lets say we wanted to play a song in A. To figure out what chords to play, you already know that you want the I, IV, and V. Looking at the circle of fifths, find the A. Your fourth will be one step counterclockwise from your A, and your fifth will be one step clockwise from your A.

The next section of the circle is the inner circle. The inner circle deals with relative minors. As you have learned, each scale has a number of sharps or flats, or, in the case of C major, no sharps or flats. When it comes to minor scales, it is the same, with Am being the scale with no sharps or flats. From this information we can discover that both C and Am use the same notes. the C scale is C, D, E, F, G, A, B, C. The Am scale is A, B, C, D, E, F, G, A. There are no sharps or flats in either scale. One way of looking at it is, to play the Am scale, you play the notes of a C scale but rather than starting on the C note, you start on the A note. As another example, the key of D consists of the notes D, E, F#, G, A, B, C#, D. The relative minor of D is Bm, which has the notes B, C#, D, E, F#, G, A, B. One easy way to find the relative minor of a key is to count backwards two notes. For example, counting backwards two notes on the A major scale gives you A, G# (Ab), F#. Therefore, your relative minor of A is F#m. Understanding the theory behind relative minors simplifies music even farther by reducing the number of scales you need to know. Rather than picking around until you get all the notes of the Dm scale, play your F major scale but start on the D note of the scale, giving you D, E, F, G, A, Bb, C, D.

Putting All Of This Into Terms On The Mandolin

“So,” you may be asking, or shouting at, or pleading with me, “What does all this abstract information actually have to do with anything”. Well, that is a very interesting question with an even more interesting answer. In, the long run, nothing. Ideally, you should get so comfortable with all this information that you forget you ever learned it and it becomes second nature to your playing. The fundamentals of music theory can be hard to grasp, but they will improve the way you think about and play music in ways you cannot imagine. Knowing the information above will help you connect everything you play on the mandolin with everything else you play on the mandolin and any other instrument, including singing. Knowing your scale theory will help you play in different keys, and your interval theory will help your overall ability to play on the fretboard, whether you are playing a simple scale on the first few frets or a crazy blues solo up above the 15th fret on your highest string. It will also help you stay grounded when the basics of theory come up (as it inevitably will) in my lessons.

Because the mandolin is tuned in fifths (G to D, D to A, A to E), every pattern you learn or come across can be transposed up, down, and across strings to any key with relative ease. Unlike many folk and bluegrass guitar players, experienced mandolin players do not need to rely on capos to play in some funny keys like B.