Fundamental music theory: Week #1

Posted by StuffonmyMind on August 10, 2021

My notes from Fundamental Music Theory course by University of Edinburgh

This is the first week of the course and it introduces us to Notes, Octaves Scales and Chords

Musical Notes

When I slap your dumbass really hard it is gonna makes a thundering sound (high). I can also snap my fingers and hear a low sound. Its the same with musical intruments, I can play something that sounds high or sounds low. However my voice can only replicate the sounds of the musical intruments and not the slap or the snap.

This is called Pitch which is the position of a single sound in the complete range of sounds.

Now we can actually plot this pitch against time using something called a Stave or Staff which is a set of five horizontal lines and four spaces that each represent a different musical pitch

This G is on the line where this symbol circles itself around is called a G-Clef or more commonly a Treble-Clef. We also see that notes start to reappear and they do so at an interval and this interval between one musical pitch and another with double it’s frequency is called an octave

This representation of notes on a sheet helped us compose and replicate music easily, More information on reading sheet notes on


An octave means after 7 notes A, B, C, D, E, F, G after which we go back to A of higher freq or the octave but if you look at a guitar or a piano you will see a lot of more than just the 7 notes.

If we look at the discreet pitches available to us in these instruments we have actually got 12 notes after which things start to repeat again. So the octave on many musical instruments nowadays isn’t divided into eight as you’d expect but rather we have 12 distinct pitch classes.

  • Distance between C and C# is called a Semitone it is the smallest musical interval and is actually considered the most dissonant when sounded harmonically
  • Distance between C and D is called a Tone

Interval is the vertical distance between two notes

Moving from C to D is actually called the Second Interval, C to E is Third. F a fourth and so on till we reach C to C which is actually the eighth interval but it is rather called an Octave. These intervals are not just from C cause we can also count G to C as a fourth so in the end it’s all about counting space

With Piano what we see here that B to C Is a second, but the C is only a semitone above B cause there are not half tones or black keys in between Whereas F to G is a second but G is actually a tone that is two semitones above F. Now they are both seconds and it’s perfectly correct to describe them that way but they do have a different quality which we will keep in mind for later


Scales are kinda like a pathway through an octave or rather just the ordered sequence of notes. For example the scale of C major is C D E F G A B C or sa re ga ma pa da ni sa which is a very common scale but the thing to note is this scale does not have the half notes or black keys which makes it the Major scale.

The important thing to note here is the relationship between these notes and for that we need to remember tones and semitones

This gives us a pattern of Tone, Tone, Semitone, Tone, Tone, Tone, Semitone. and this pattern of two tones and then a semi-tone followed by three more tones and a final semi-tone is what makes this scale sound the way it does.

Each note on it’s own doesn’t actually mean that much and what’s important is how they sound next to each other in the context. How they stand next to each other and build up relationships between one another or in musical terms this is what gives us the quality of the scale.

The letter name that the scale is named after is called the tonic. For the C Major scale C is the tonic and for F Major F is the tonic.

The C major scale we saw above is also what is called a Diatonic Scale or between two tonics. Diatonic scales have seven notes with some pattern of five tones and two semitones.

Let’s take A as our tonic instead of C

This is the Natural minor scale / Aeolian mode which is still a diatonic scale but a different sequence of tones and semitones

The Seven Diatonic Modes

C-major/ Ionian I W–W–H–W–W–W–H C–D–E–F–G–A–B–C
D Dorian ii W–H–W–W–W–H–W D–E–F–G–A–B–C–D
E Phrygian iii H–W–W–W–H–W–W E–F–G–A–B–C–D–E
F Lydian IV W–W–W–H–W–W–H F–G–A–B–C–D–E–F
G Mixolydian V W–W–H–W–W–H–W G–A–B–C–D–E–F–G
A Aeolian/ natural minor vi W–H–W–W–H–W–W A–B–C–D–E–F–G–A
B Locrian vii H–W–W–H–W–W–W B–C–D–E–F–G–A–B

We can play the same song just with a different mode to make it sound different !! cause each mode has a special quality or mood to it

An exercise would be to Play a song across different modes or just play the octave in different modes to feel the difference between them

There is also the chromatic scale. While the diatonic scale uses only seven notes, the chromatic scale uses all 12 pitches or note tones in either ascending or descending order separated by semitones.


A chord is the layering of several tones played at the same time and they kinda define the harmony of a song.

If we go back to our C major scale and consider notes from C to G

C   D   E   F   G
  T   T   S   T
  12  34  5   67

We note 7 semitones bewteen C and G cause its made of 3 tones and a semitone, Also C and G played together sound kinda crisp and looking at the interval we see its a fifth

We give this interval a quality and call it The perfect Fifth cause it spans seven semitones

Similarly C to E is a Third and is made of two tones or 4 semitones which makes it a Major Third

This is the Cmajor chord C E G or its the Cmajor Triad cause it’s a chord made of 3 notes

We can do the same exercise with Aeolian or the natural minor scale to derive the Aminor triad A C E

A   B   C   D   E
  T   S   T   T
  12  3   45  67

Even here we have the Perfect Fifth with A and E while A and C form the third interval but the difference here is that the third interval A and C is made of 3 semitones which makes it a Minor third

With every scale this subtle difference in the number of semitones tend to give the chords a distinct sound or even a feeling.

  • Perfect Fifth + Major Thirds (4 semitones) => Major Triad (C major)
  • Perfect Fifth + Minor Thirds (3 semitones) => Minor Triad (A minor)

We can repeat what we did for C and A to get the other triads across scales but lets do it one last time starting with B

B   C   D   E   F
  S   T   T   S
  1   23  45  6

Now B D F is a weird one since B and F have only 6 semitones in between them which is one smaller the perfect fifth so we will call this the Diminished Fifth we also have a minor third which makes it a Dimished triad

Some common triads

  • C major (C). C - E - G
  • D minor (Dm). D - F - A
  • E minor (Em). E - G - B
  • F major (F). F - A - C
  • G major (G). G - B - D
  • A minor (Am). A - C - E
  • B Diminished (Bdim). B - D - F

Primary Chords

Let’s turn da focus on the 3 Major chords C major (Tonic) CEG F major (Subdominant) FAC and G major ( Dominant) GBD. These have become important through time in common Practice classical music as well as a lot of Jazz and Pop and Rock that it’s sometimes referred to as the Three Chord Trick.

Let’s look at the major scale and see how each note can be harmonized by one of these three chords

  • C Note -> Cmajor or Fmajor (Since both these chords have C in them)
  • D note -> Gmajor
  • E note -> Cmajor
  • F note -> Fmajor
  • G note -> Gmajor or Cmajor
  • A note -> Fmajor
  • B note -> Gmajor

Confining ourselves to just the white notes of the piano and C major scale we found three different kinds of triads and also found all sorts of internal relationships which already gives us the possibility of making music :)