I get a lot of questions about music theory. I thought it would be great to tackle some of these questions and post them on this blog for anyone who might want to chew on ideas in music theory and use them as a jumping off point for making new music or gaining some clarity on the songs they are already studying. So here is my first attempt! Keep in mind, this is a tough one, so until you have a good grasp on the Major Scale, I’d suggest holding off on this explanation until after you learn about that first.
I am often asked questions like, “What is a mode? How does it differ from a key or tonality or a scale? How do modes and keys interact?”
I’ll unpack a few of these terms.
A “key” is the term for a group of specific notes. If you tell me we’re going to play a song in the key of D Mixolydian, it means chiefly two things:
- “D” is the main note in the song, or home note, the note from which the rest of the song’s melodies and chords originate, the note that makes us feel like the song has reached resolution. Some people call this the “tonic” or the “Do” in Do-Re-Mi of Moveable Do Solfege.
- When we play a Mixolydian scale from “D,” we’ll hear all the tones used in the song.
That’s a mouthful of music theory that fits in only a few words.
So what does it really mean to play a scale? Well, the “scale” is just a simple way to lay out all of the notes presented in a piece of music in order, typically from the lowest to the highest. We refer to the scale as if it were a dictionary, and we apply the scale in myriad ways… we can transcribe melodies into the degrees of the scale, create lead guitar parts from a scale, write bass lines; the scale is also used to show the relationships between chords or entire chord progressions, to help us see the connections between different songs across the whole spectrum of artists and genres we encounter, to provide a basis for improvisation, to aid in re-arranging, etc. Again, it lays out all of the notes we might hear or use in a song in a clear way. A scale, in this sense, is maybe not so different from a painter’s palette with its colors arranged in a gradient.
The term “tonality” is more loose… it has more to do with the mood/flavor/feeling the musical tones give the listener; it describes the experience of the listener. The idea of the tonality of a piece is, in this sense, distinct from the word “key,” which is a more specific word: where “key” refers to the actual set of notes, “tonality” refers to the way we perceive those same notes. They are by definition closely associated, so their meanings can have some overlap.
Now for the crazy part: a “mode” is a way to think of a particular key or tonality as a subset of another key we are more familiar with; but in actuality–once introduced and grasped–is experienced as if it were distinct from that key. For example, one can listen to a song in the key of G Mixolydian and another in the key of A Aeolian and never recognize that they are at all related even when, in fact, these two scales are comprised of the exact same set of notes. They are known as the fifth and sixth modes of the key of C Major.
These modes can also be rendered more simply using any equal-width font:
MODES OF C MAJOR:
C _ D _ E F _ G _ A _ B C
D _ E F _ G _ A _ B C _ D
E F _ G _ A _ B C _ D _ E
F _ G _ A _ B C _ D _ E F
G _ A _ B C _ D _ E F _ G
A _ B C _ D _ E F _ G _ A
B C _ D _ E F _ G _ A _ B
And so the “Key of C Major,” which is usually the first big concept any serious student of western music comes across, is actually much greater than it seems. In practice, most of us learn about C Major and play the C Major Scale when, in truth, we are really only playing C Ionian, the first mode of C Major. So, let this be our introduction to the real C Major, this set of notes with subsets of notes that yield amazingly different results. Become familiar with C Major and its modes (D Dorian, E Phrygian, F Lydian, etc.) which, by definition, use the exact same notes (the white keys on the piano) to produce wildly varying tonalities.
To hear what I’m talking about, try playing only with the white keys on the piano, or natural notes on any instrument. But start and end on G, and then try again with A. You’ll notice G Mixolydian sounds familiar; rock and folk seem to be full of examples of Mixolydian.
Here are some quick Mixolydian examples:
- the main riff for The Beatles’ “Day Tripper” (E Mixolydian),
- “Casimir Pulaski Day” by Sufjan Stevens (Eb Mixolydian),
- “Cinnamon Girl” by Neil Young (mostly D Mixolydian but a touch of D Dorian),
- Led Zeppelin’s “Ramble On” (E Mixolydian),
- “Times Like These” by Foo Fighters (D Mixolydian), and
- “Give Up the Ghost” by Radiohead (D Mixolydian) all employ the Mixolydian tonality.
A Aeolian sounds totally different… it sounds melancholy or dramatic. Just take a listen to
- “Street Spirit” by Radiohead (A Aeolian),
- “Minnesota, WI” by Bon Iver (C Aeolian), and
- the intro and verse of “Slow Show” by The National (C# Aeolian) are great examples that Aeolian flavor.
So, while the fifth and sixth mode of C Major are experienced subjectively as something entirely different from the first mode, they are, on an objective level, the SAME as C Major! Indeed, the same set of notes used to play “Happy Birthday” and “London Bridge” can also yield the tune to every one of the songs listed above (ignoring the fact that the songs are in different keys, which we will get to next). This is why the term “mode” is a challenging idea, but an amazing one. It alludes to both an objective and subjective musical reality in one word.
So modes and keys? What’s the difference?
Any given piece of music may change keys. This becomes obvious when one set of notes succeeds in describing one section of the song, and then fails in describing another. But even when this happens, the mode may remain the same. For example, if I play in the key of C (and the first mode, a.k.a. Ionian, is always assumed when I say “key of ”), I can change in the middle of the song to the key of A, and still be in the same Ionian mode, I would just be in A Ionian (with three new sharps, F#, C#, and G#). I can also change modes within a song without changing the key. Yes, a song that doesn’t change keys can still shift your perception of its tonic! There are a few songs that come to mind on this subject:
Let’s take “Untitled 8” by Sigur Rós, one of my all-time favorites.
It starts out in what appears to be D Major/Ionian (but never gives it away fully, so we are left guessing), but eventually reveals itself to be D Mixolydian. You see it when the main guitar part drops to C, revealing a b7, the key of D Mixolydian (the fifth mode of G Major) in what you might call the pre-chorus of the song. And then in what you might call the chorus of the song, it flirts with G Ionian! And eventually, it migrates to E Aeolian and stays there for the last brooding, powerfully dark section of the piece that still gives me chills a decade after I first heard it. And the glory of this is that you can play one scale, G Major, and capture every single note in the epic journey of the 11:45 minute song. D Mixolydian for the verse and pre-chorus, G Ionian in the chorus, and E Aeolian in the build-up to the song’s climax… three different tonalities, but all one scale!
It’s incredible what range of emotions can be captured by only seven tones.
Another love of mine, Miles Davis’ legendary album, Kind of Blue, is famous for having used modes as a jumping off point for improvisation. Miles simply gave his band some manuscript paper with basic scales on them and indicated which notes were the tonic in each (mode) and then they played some great tunes to contextualize these improvised modal explorations. To this day, people still call that album an example of “modal jazz,” and the term is very accurate. It also became the best-selling jazz album of all time!
So… in sum, the study of modes gives us an incredibly deep appreciation for how when different notes are treated as the tonic, the same notes can be experienced in different ways. But we had to go through the key of C Major to understand it.
Hope that was helpful! If you found this helpful, leave a comment, share it with others!