Capital-M Music

Music Theory Guides

How to Think About Modes

by Richard Bruner

I made the first version of this guide for a friend I was informally tutoring in 2022 before I started my master’s program at California State University, Northridge. He had taken some music theory classes and we were talking about theory one day when the topic of modes came up. I also used that version of the guide as the basis for my teaching demonstration in CSUN’s Teaching Music in Higher Education class in the fall of 2023. This version of the guide has been lightly expanded from the original, and I have plans to add more to it in the future - maybe some parts about modal harmony (this version focuses on the concept of modes and melodic uses of modes), and some musical examples that demonstrate use of modes.

I’ve heard from other people over the years, both directly and from reading comments online, that many people seem to find the idea of modes confusing. I think the confusion comes both from being unclear what modes actually are, and also from the fact that there are several common modes and they have “scary” names (mostly based on various Greek islands or tribes), which look complicated to us Americans today. I always thought that made them interesting-sounding and I was excited to learn more about them when the topic came up in my classes. So let’s start with a basic understanding of what modes are, and then I’ll show two ways of thinking about them - one that is the most common way, and then one I like better.

So what is a mode? The word “mode” in music theory refers to the way a scale is set up. If we go back to the way we usually talk about major and minor scales, we say that they are patterns of half-steps and whole-steps (generally, with the occasional augmented 2nd thrown in). If you start on any given note, and then you play a particular sequence of half and whole-steps, you will get a major scale based on that note (that sequence is W-W-H-W-W-W-H [W=Whole-step, H=Half-step). Minor scales have their own patterns. In older harmony textbooks, you will often see references to the “major mode” or the “minor mode(s)”, and this is where we get into talking about the differences between parallel major and minor keys (starting on the same note - C Major vs. C Minor, etc).

These days, when we talk about modes, we are more often talking about the seven “church modes”, and you can move beyond them to modes on other scales too eventually. When you learn about the “relative major / minor” scales, one way they talk about them is to say “start with a major scale and then go two steps down from that starting pitch to get its relative minor” (or two steps up from minor to get relative major). This takes you from C down two (B, A) so A minor is the relative minor to C Major. If you start on G, then it’s ([G] F# E) so E minor is the relative minor, etc. We can expand upon that concept to derive other scales as well, and this is where the church modes come into play. We start with a major scale and then keeping the same pitches we start on various other notes to derive each of the modes in turn. This is how it’s most often taught to begin with, and that leads us to the first way of thinking about modes.

Here is the most common way of introducing modes. The idea is that if you play only the white keys (natural notes) on a keyboard and start on each note in turn, you will create the seven "church modes". This is true, and is one way to derive the modes, but may not be the most effective way to think about using the modes. This is what you get if you do this:

This is my preferred way to think about the modes. I call it the "Brightest to Darkest Modes" method. The idea here is that starting on one note there are three "major-ish" modes, three "minor-ish" modes and one odd one out. "Major-ish" vs. "Minor-ish" is determined by the major or minor 3rd degree, and then each mode either is major or natural minor, or is one raised or lowered half-step away. Raising a note makes the scale brighter sounding, lowering a note makes it darker, and major is brighter than minor. Here's the resulting order using a starting note of C (red indicates a lowered pitch relative to major or natural minor, green indicates a raised pitch):

Locrian mode is the odd one out because it lowers two scale degrees, and one of them is the 5th scale degree, which causes the i chord to be diminished. This is unusual and difficult to work with because the i chord is normally the most stable chord and diminished chords are unstable. This mode can be used but it will usually have an unsettled feeling and is best when that is the desired context (in that context it can be excellent, i.e. certain dramatic contexts in film scoring or anywhere else that is the intended effect). Other modes either have a major or minor I (or i) chord and melodically work more or less like major and minor scales with a bit different of an emotional feeling. The benefit of this method from a composer's perspective is that you can control the mood of the piece by thinking about how bright or dark you want the piece to be and picking the mode accordingly.

One thing to notice with this sequence of modes is that each time we go from one to the next, we lower one note compared to the mode before it. When we get to Locrian, the only note we haven’t yet lowered is the first scale degree, so if we then lower that note, we wind up in Lydian starting a half-step lower. So you could in principal play through this sequence of modes, lowering one note each time, and then play down the entire keyboard from top to bottom. It would take a very long time to do it, and I don’t think there’s much point in doing it across the whole keyboard, but I do think it would be useful to practice this exercise a few times (maybe even on every possible starting note in one octave) to get comfortable with the patterns involved.

The other thing to keep in mind with modes is that they are the conceptual equivalent of major and minor scales. They are simply patterns of half steps and whole steps and can be applied to any starting pitch, as mentioned at the top of this guide. The issue with the "white keys" method of teaching modes is that it can be easy for students to get hung up on "D" dorian and "E" phrygian, etc. and wind up thinking there is some connection between D and dorian, or F and lydian. But just as it wouldn't make sense to talk about how major is specifically related to Bb and not Gb, there is no necessary connection between D and dorian, or G and mixolydian - they just happen to be the starting notes for those modes if you stick to the white keys on a keyboard. Bb mixolydian makes total sense. Here's how to make it:

Mixolydian is "major-ish", so start with Bb major:

Then we are going to lower the 7th scale degree a half-step, so our A natural is going to become Ab, and that will give us Bb Mixolydian:

Another example: E dorian. Dorian is a "minor-ish" mode, so start with E [natural] minor:

Then raise the 6th scale degree by a half-step, so C natural becomes C#:

Using this trick will allow you to rapidly figure out any mode once you become fluent with the differences.

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One other thing to notice is that if you look at E Dorian, you’ll notice it has two sharps. The major scale that has two sharps is D Major. If you look at E compared to D, you’ll see that E is the second scale degree of D, and if you go back to the White Key Method, you’ll see that Dorian is the “second” mode.

Look at our Bb example as well - Bb Mixolydian has three flats (remember the Bb at the bottom and top are the same note, so you’d only count it once). The major scale with three flats is Eb major, and Bb is the fifth scale degree of Eb major. Back to the white keys method - Mixolydian is the “fifth” mode.

I don’t think the white keys method is the best way to approach conceptualizing modes, but the order that you get from that method can still be used for calculating modes from the number of sharps or flats. I use this in a practical sense when I play the tin whistle, as this is how I figure out which key of tin whistle I need to play a tune in any particular mode (tin whistles are basically diatonic instruments, so I have them in most of the keys). This also leads to our final concept for now:

One final thing to talk about here is the idea of mode signatures. The key signature is a familiar concept in tonal harmony music theory, the kind normally taught first in general music theory classes. Students are taught that if you see two sharps in the key signature, then you are likely dealing with either D major or B minor, and you can tell which normally by looking at the first note of the piece (Pro tip: the last note is actually a safer one to use as it's more likely to be the 1st scale degree than the first note, though either is probably going to work. If they are the same then it's almost a guarantee that's right).

In modal music that is aimed at people who are likely to not have had a full music theory course yet (educational music for high school orchestras or younger piano students, for example) they will often use a bit of a cheat. You will often see the key signature of the major or minor key with the same starting note depending on whether the piece is in a "major-ish" or "minor-ish" mode, then accidentals will correct to the real mode (A mixolydian is "major-ish" so they'd use A major (3 sharps) for the key signature and then cancel the G# with accidentals at every occurance to lower the 7th scale degree).

But you can also use "mode signatures" which are more common in music that is in a style that uses modes frequently and is not necessarily educational in nature. For example, Celtic fiddle music is modal, and non-educational tunebooks of fiddle tunes will often use mode signatures without comment. This is where we only include the sharps or flats that are actually used in the tune in the mode signature, so A mixolydian would show two sharps with no accidentals. This means that any given mode signature could be one of seven possible modes (for two sharps, D Ionian, E dorian, F# phrygian, etc) rather than two (D major or B minor), but in practice it's often not that bad. To go back to Celtic fiddle, in those styles, Ionian, Dorian and Mixolydian are the most common modes, with some Aeolian and very few of the other modes, so you only have 4 (or even 3) modes to consider, and from there you can use the last note of the tune trick to figure out which in most cases.

Mode signatures are useful because they declutter the music and make it easier to read. They also reflect the modal nature of the music more than key signatures with accidentals do. Once you are familiar with the style of music in question and know what to look for they can simplify your life rather than make it more complicated.

————————— Everything after this point is under construction starting May 27, 2024. Things may shift over time—————————