An Introduction to Modes

This article will give you a basic understanding of what a 'mode' is in music, provide two methods of identifying modes, and give examples of modes in popular music to practice their identification.

What is a mode?

In music, the basic building block of melodies and harmonies are pitches. A pitch is a specific frequency of sound, in the equal temperament tuning system of Western music (what we focus on in AP Music Theory, and music in North America and Europe in general), there are twelve of them. Pitches can be arranged in a multitude of different ways. If a subsection of these pitches are played simultaneously, they are called a chord, whereas if they are played in sequence, they are called a scale. Hopefully this is review!

In unit 1, we learned of a specific way of ordering pitches to get a major scale. Remember, a major scale can be constructed using the W-W-H-W-W-W-H formula, but it is certainly worthwhile to memorize the key signatures of each key using the circle of fifths. But what would happen if we changed the formula we used to derive a major scale? For example, what if we used this formula: W-W-W-H-W-W-H?

You can see that there are a myriad of different possibilities. This is what a mode is: simply re-arranging the notes of a given scale (in this case the major scale) to create a new mode of that scale. This can be done with the harmonic minor scale to get the harmonic minor modes and the melodic minor scale to get the melodic minor modes, but those are much rarer and outside the scope of the AP Music Theory. Thus, for this article, we will consider the major modes.

So how should we go about learning the major modes? I'll propose two different methods. You should choose whichever method allows you to quickly identify a given mode (both written and in music). In my opinion, this second method allows for an easier time with identification, but choose whichever one suits you best.

Learning the Major Modes: Method 1

This method is simply an extension of the basic explanation I offered earlier. Consider the C major scale:

C D E F G A B C

In fancy mode language, we call this the ionian scale on C.

To derive the A minor scale from this ionian scale, we can use the same pitch collection, but start on A:

A B C D E F G A

In fancy mode language, we call this the aeolian scale on A.

Thus, we can see that to derive modes, we can simply start on a different note of a given ionian scale, shifting each of the half and whole steps accordingly. Let's derive the rest:

As you can see, there are eight different major modes that can be derived. The issue with this method is that it is not easy to identify what makes each mode unique, and therefore it is difficult to understand what each mode sounds like. Let's look at another method.

Learning the Major Modes: Method 2

This method involves analyzing which notes of each major mode make it unique. To do this, we can split up the modes into two categories: those whose third is major (called the major modes), and those whose third is minor (the minor modes). Then we can compare them to the notes we would expect to find in the ionian or aeolian mode respectively. Let's transpose each of the previous modes to start on C.

As we can see, each mode has a unique color note that makes it unique compared to the other modes. Identifying this color note in a melody or chord will help you to identify what mode the melody or chord is in. For example, a "Lydian chord" just means that the chord has a raised fourth scale degree within it. For example, check out this track from Wall-E: 

The first chord establishes Ab as the tonic, but the second chord introduces a D natural, which produces a lydian sound.

Learning the sound of every mode is important, so let's do some more examples.

Learning the Sound of Modes

Let's go through some examples, identifying what modes are used. We'll go in the order of "happiness," starting with what many people believe are the happiest modes and going to the most intense/sad modes.

Lydian (M#4): A common way of using this mode is to vamp between the major I and major II chords of a given key. This introduces the #4 into the harmony. It is often associated with extreme happiness or brightness. See this track from The Legend of Zelda: Ocarina of Time. 

Ionian (M): This is the most common mode. If a piece's mode isn't discernible, it is likely ionian. See this track from Animal Crossing: New Horizons (which simply walks up and down a major scale):

 Mixolydian (Mb7): This mode can be identified with its signature b7 scale degree. I-bVII vamps are a signature. It is often associated with smoothness, or soulfulness. Here is an example of what I mean:

Dorian (m#6): Listen for the raised 6th scale degree. This mode is often associated with mysticism, or dungeons in video games. It sounds almost like the lower half is minor and the upper half is major. Here is an example:

Aeolian (m): Listen for a generally minor sound, but ensure that there is no leading tone. This mode is generally associated with sadness, nostalgia, or depression. If it is none of the other minor modes (and it isn't harmonic or melodic minor), then it is likely aeolian. Here is an example:

Phyrigian (mb2): This mode often uses the b2 to sound intimidating. Think music before a boss fight in video games. See this example, where the marimbas oscillate between the i chord and the bII chord: 

Locrian (mb2b5): This mode is very unstable due to the tonic chord being a diminished chord. The sound of this mode thus also sounds unstable, wanting to resolve strongly back to the 2nd note instead of the first. Here is an example:

Revisiting the Phrygian Half Cadence

Now that we have learned about the Phrygian mode, why do you think the Phrygian Half Cadence is called that? As a reminder, the phrygian half cadence is the cadence of vi6 to V in a minor key.

The reason is because the bass motion in such a cadence is a descending half step, which is reminiscent of the half step motion between the tonic and color note (b2) in the phrygian mode.