In this lesson, we will learn about one of the most important topics in music theory: intervals. Music interval is the basement to master other topics, such as chords and scales. Want to be able to build any kind of chord? Learning intervals is the key.

An interval is the distance between two pitches. The smallest interval in Western music is the semitone (or half step). Two half steps will form a whole step. Using a piano keyboard as an example, a half step or semitone is the shortest distance between two keys:


Interval Number

Each interval will have a number – for example 1, 2, 3, 4, 5, 6, 7, 8 – which is based on counting the lines and spaces on the staff:


A simple way to quickly understand an interval number is to observe the white keys of a piano. Having C as the reference key, the interval between C to D will be a second (there will be two white keys, C and D). C to E will be a third (three keys, C, D, and E), and so on. With that in mind, let’s parctice: what’s the interval between E and A?

The starting point will be E. How many white keys between E and A (first and last included)? There are 4 keys: E, F, G and A. So, the interval between E and A will be a 4th:


Interval Quality

An interval also has another identifier: interval quality. There are 5 types of interval quality: Major (M), Minor (m), Perfect (P), Augmented (A) and Diminished (d). Let’s start with the first three. To do that, we must remember 2 important rules:

Major and minor intervals: will occur only with 2nd, 3rd, 6th and 7th intervals.

Perfect intervals: will occur only with unison, 4th, 5th and 8th intervals.

When you get familiar on how to build major, minor and perfect intervals, will be easy to build augmented and diminished ones.

Major 2nd

As we’ve seen above, a 2nd interval can be major or minor. Learn how to identify a major 2nd – and the minor 2nd will come automatically. A major 2nd will always be formed by a whole step (or 2 half steps) between two notes. So, let’s use the example below:


Let’s always start from the lowest note. So, what’s the interval between C and D? Here’s what we already know:

– C and D form a 2nd (interval number);

– A 2nd can be either major or minor;

– A Major 2nd will have a whole step between the notes.

Now all we need to do is to determine the distance between C and D. Notice that there are two half steps (C to C# and C# to D). Two half steps (or a whole step) – it’s a Major 2nd.


Some examples of Major 2nd: D to E, F to G, G to A, A to B, B to C#, etc.

Some Major 2nd examples


Remember, if the distance between 2 notes is a whole step, you will be looking at a Major 2nd.

We will continue to learn about intervals in the next lesson.

Happy productions!