Music Theory 101: An Easy Guide to Understanding Intervals

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Keep reading to learn about intervals and test your knowledge with our interval study quiz.

What is an Interval?

In music theory, an interval refers to the pitch distance between two notes. It is determined by counting the number of letter names and the distance in pitch classes and can be classified by their distance and quality, which plays a fundamental role in harmony, melody, and chord construction.

Still confused? Okay let’s break it down further.

Understanding Music Intervals

1. Intervals are the distance between 2 notes.

2. The interval number is determined by the distance of the musical letters. Just remember to include both the starting and ending notes when counting.

A melodic interval is when 2 notes are played one after the other, like in a melody. A harmonic interval is when 2 notes are played at the same time, such as when you are harmonizing.

4. Intervals can be identified by its quality: major, minor, perfect, augmented or diminished. The intervals you will first encounter are perfect 1 (unison), minor/major 2nd, minor/major 3rd, perfect 4th, perfect 5th, minor/major 6th, minor/major 7th, and perfect 8th. To determine an interval quality, there are 2 methods: the Half-Step Method and the Scale Method (refer to #7)

Some additional things to consider:

     

      • Perfect intervals are essentially two notes that belong in a major key and can only be in unison, 4ths, 5ths, and octaves. They sound harmonious and have a pleasing quality about them

      • Augmented intervals are a half-step larger than a perfect or major interval

      • Diminished intervals are a half step smaller than a perfect or minor interval

    Interested in improving your interval ear training skills? Visit here to find out more about our Interval Ear Training Package.

    5. Each interval is made up of a specific number of half steps. You can also think in whole steps too. A half step (semitone) is when you go up or down 1 step to the very next key. It does not matter if it is a white or black key, as long as it is right beside it. A whole step (whole tone) is when you go up or down 2 steps (again, does not matter if it is a white or black key).

    6. Intervals are identified by using the lowest note as the tonic (first scale degree of a scale).

    7. Below are the 2 methods you can use to identify intervals and its quality.

    The Half-Steps Method

    You can determine the interval and its quality by counting the number of half steps between the two notes.

    This method is a quick and easy way to identify your intervals, however we recommend you try the Scale Method too in order to understand intervals more comprehensively.

     

    The Scale Method:

    Another approach is to see if the higher note fits into the key of the bottom note.

    If you need to determine what a minor 3rd above C is, first you will proceed with the same steps previously mentioned: identify the 3rd note in the C major scale. Secondly, take that 3rd note a half step lower.  For example,  a minor 3rd above C is Eb because the third note in C major is E, and if you take E a half-step lower, you get Eb. 

    Now that you have a basic understanding of intervals, let’s practice identifying intervals by ear. Find out more about our Interval Ear Training Package.


    QUIZ TIME

    Now try these examples yourself using either the half step or scale method.

    What is a perfect 5th above D?

    What is a minor 7th above C?

    What is a major 3rd above G?

    Here’s a bonus question that will be sure to make you think!

    What is a perfect 4th BELOW A?

    For the answer key or more quizzes like these, fill in the form below.