Now we know the musical alphabet, we can look at the intervals between them. An interval is basically the gap between two notes. Whilst counting the semi-tones between 2 notes is very helpful, we will need a quicker way to count the distance between the gaps, and this is where intervals come in.
So if we were to jump from an A note to a D, that is 5 semi-tones. Each number of semi-tones has a matching interval. We’ll look at which ones pair up but before we do that, we need to know what the names of intervals mean.
There are 3 main types that we will be looking at and 2 “special” intervals.
The first is Major. This is an interval that fits the key and will generally sound like it works with music. These intervals usually sound quite happy in the music.
The second is Minor. Minor intervals are a semi-tone below a Major interval. They don’t always sound like they match the key or the music but this can be a good thing because it makes the notes stand out and more memorable. They can sound a little sad in the music too.
2nds, 3rds, 6ths, and 7th, can be Major or Minor, depending on the sound you want.
The third is Perfect. These intervals don’t have a major or a minor. These notes are the most important ones as they are the backbone of the ‘key’ or music. These will always fit the music. If you play a fret below or above, they will sound very out of place with the rest of the song. This can be useful if you want the tension it gives.
4ths, and 5ths are always perfect.
They are the main 3 intervals you will see. You will see these ones more than the others as they are used for scales, chords, and melodies. You’re sure to come across them soon, so make sure you are familiar with their names!
The last 2 are related to the Perfect intervals. A perfect interval will always fit the music, but if we move a Perfect interval a semi-tone down, we get a diminished interval. This creates a very out of place note and sounds like doesn’t belong at all. We can only get these notes on 4ths and 5ths.
If we move the interval up a semi-tone we get an augmented interval. These again, sound very out of place with the rest of the music and are only to be used on a Perfect interval. We usually use them in special cases with certain scales or certain chords. You may not come across them that often, but it helps to know them when we get to the more complicated chords.
Now we have gone over what each interval means, we can match them to their semi-tones. I have highlighted the intervals based on major (green) and minor (red) gaps. The ones marked in yellow are perfect and the ones in purple are diminished/augmented.
[insert table of semitones and intervals]
Instead of counting 5 semi-tones of the fret board, we now know that we only have to move to a Perfect 4th.
This is important because we can look at the guitar and move a perfect 4th instead of counting the semi-tones every time, which will be confusing and difficult on the spot! This will help us play melodies and chords in the future. To understand this completely will take a little bit of time, so don’t rush everything. A good way to start is by knowing the main ones such as the Perfect intervals and using those as a halfway point then count up the semi tones from that point. so testing yourself with semi-tones and how far away will help you a lot later in the lessons!