And we’re back to diving in to music theory!
The next several posts will be spent looking at different intervals in music. Knowing intervals helps us with a lot of things:
- We can train our ear better to sing and play things if we understand and know intervals.
- We can know and remember how to build chords by studying intervals.
- For bass players, intervals are especially important for playing fills and going from chord to chord in new ways.
- Knowing intervals help us understand how to read music better.
Basic Intervals
There are several intervals in music theory – some of which are common to see in popular music and some of which are not-so-common! We’ll be looking at the common ones for now. They are:
- Major and Minor Thirds
- Major and Minor Seconds
- Perfect Fourths
- Diminished and Augmented Fourths
- Perfect Fifths
- Diminished and Augmented Fifths
- Major Sixths
- Major, Minor, Diminished and Augmented Sevenths
Thirds in General
To our contemporary ear, thirds (particularly major thirds) are probably the interval that most of us think of as “pretty” or “nice.” What’s humorous, however, is that in the middle ages thirds were considered to be dissonant and not pretty at all. So what is a third?
A third is just like it says it is – an interval of notes that is three notes away from the original note. For instance: C, D, E. C to E is a third. Or, going down from C: C, B, A. C to A is a third.
The Catch
The catch to many of our basic intervals is that there is no set “third” or set “fifth.” There are several different types of each interval. Let’s take a look at major and minor thirds.
Major Thirds
We’ve established that a third is a distance of three notes away from the original note. But it’s not quite that simple. A major third is the distance of four half-steps (the very next piano key, going from white to black to white, etc. or the very next guitar fret) away from the original note. So, if you were to start on C and count up four half steps you would count C#, then D, then D#, then E. From C to E (the distance of four half-steps) is a major third. The key is that the half-step counting doesn’t start from C, it starts from C#. That confused me for a long time. It’s good to know that we need to count up four half steps and not just three notes every time because if you’re trying to build a major third in the key you’re playing in, it’s not going to work to just count up three notes from every note of that key.
For instance, in the key of C, you couldn’t just start on E, count E-F-G and get a major third. You’ll have to count F-F#-G-G# (four half steps) to build a major third from E, realizing that you’ve now left the original C key signature. If you would just count up three notes from E and land on G you would end up with a minor third.
Minor Thirds
Minor thirds are an interval that to our contemporary ears might sound sad or melancholy. Minor thirds are also the distance of three notes from the original note, but with one slight alteration. Instead of counting four half steps away from the original note you only count three. So, from C, a minor third would be counted this way: C#, D, Eb (or D# – we’re calling it Eb because we’re lowering the third note – when a note is lowered, it is flat and when it is raised it is sharp). You could also find a minor third by counting up three notes from the original (C-D-E) and then lowering the last note a half step (changing E to Eb). You could also count downward to arrive at a minor third: From C – B, Bb, A – three half steps brings us to A. From C down to A is a minor third.
Intervals within the Key Signature
As I mentioned above, certain intervals will naturally be in every key signature. The first note of any major key to the third note of any major key will always be a major third. The third note in any major key to the fifth note in any major key will always be a minor third. Play around with figuring out how to build major and minor thirds from each note of the key and you’ll be able to see what always works in every key.
Simple Ear Training To Remember Thirds
A great way to remember what a major third sounds like is to sing “Oh When the Saints…” The first two notes of that familiar melody (the distance between ‘oh’ and ‘when’) make a major third. A great way to remember what a minor third sounds like is to sing “What Child is This (Greensleeves Melody.” The first two notes of that melody form a minor third. Musictheory.net has a great interval ear trainer and several other exercises you can use to learn all of the intervals.
Building a Basic Chord
Your very basic chords are built from major and minor thirds. A major chord is built with a major third on the bottom (C to E or D to F#) and a minor third on top (E to G or F# to A). A minor chord is built similarly, only flipped – a minor third on the bottom (A to C or B to D) and a major third on the top (C to E or D to F#).
Next: Major and Minor Seconds.
Here is a very detailed and much more technical overview of intervals.
