Intervals are probably the most important aspect of music theory to know if you want to do serious and regular songwriting.
Before reading this article, you should know several things about music theory, namely:
1) How to read music from a staff,
2) A good understanding of notes,
3) Knowing how to play piano, or play guitar off of sheet music would help you to understand the article better.
To start off, there are two kinds of intervals: melodic and harmonic. Melodic intervals, as you can guess, carry melodies. That meaning, two notes played seperately are two melodic intervals. Harmonic intervals are notes being played at the same time.
The names of intervals:
Intervals have different names, according to the distance apart from the root note. Taking the key of C Major (CDEFGABC), the names are as follows:
C (root note)
C sharp (minor second)
D (major second)
E flat (minor third)
E (major third)
F (perfect fourth)
F sharp (minor fifth, augmented fourth)
G (perfect fifth)
G sharp (minor sixth, augmented fifth)
A (major sixth)
A sharp (minor seventh, augmented sixth)
B (major seventh)
C (octave, or perfect eighth)
Naming an inverval:
To name an interval, all you need to do is count the amount of notes between the two tones, including the first note.
So, for example, you want to find out what amount of an inverval is between C and G. Here's how you do it
There is a total of five notes. Therefore, G is a fifth of C. However, there could be several kinds of fifths. Diminished, minor, major, and augmented.
A diminished interval is two semitones (a whole tone) below a major interval. Therefore, F would be a diminished fifth in the key of C major.
F sharp would be a minor fifth, G would be a major fifth, and G sharp would be an augmented fifth.
So, let's say G sharp is the desired note.
Five notes. Now, since it is G sharp, it is one semitone ABOVE G natural, so it as an augmented fifth. This is important to know because when you change key signatures, naturals, flats and sharps will change. I am using C major for the sake of simplicity. However, using the key of F major, the following notes are used
So, if we are trying to find out what interval is between F and B, everything changes.
There are four notes. Now, because it is B, and not B flat, it is an augmented fourth, or a minor fifth, depending on what you prefer to call it. However, a B flat would be a perfect fourth because B flat is the fourth degree of the key of F major.
How to use intervals to write songs:
Using your new knowledge of intervals to write songs is not very difficult. Using power chords, with the low E as your root note (sixth string played open), strum E5. That is your root chord (or note, if you will). Move up one fret. You have just played a harmonic interval, a minor second. Move up again. You have reached a major second, or diminished third. Move up to the third fret, strum. That is a minor third.
Moving up to the fourth fret, you have played a major third. Now, try playing this:
Play it moderately fast, and make the last chord sound short.
That riff takes you from a minor third, diminished third (major second) to a minor second. If played in the right strum pattern, that can also be heard in the song "Just" by Radiohead. Not bad for a bunch of boring theory.
To summarize intervals to coincide easier with guitar playing, here's a quick guide. It is implied that hte number of semitones is the amount of semitones from the root note.
Major third: 4 semitones (four frets)
Major fifth: 7 semitones (seven frets)
Major seventh: 11 semitones (eleven frets)
By using this knowledge, you can also form chords based on the intervals between the notes, by just thinking about the amount of frets up from the root note everything is.
Thanks for reading my article, and I hope that you use what I've taught well.
- Backup Guitar.