The Confusing Lingo Of Music Theory

We recently got an excellent music theory-related question from a student which reflected a misunderstanding of terms that confuse many students and wanted to share it with everyone (because as we all know, if one student has a question, others do, too!)

[From the student]: I noticed the [theory] course does not cover any understanding on left-hand bass accompaniment with modes. I struggle daily trying to practice because I do not know what bass note goes with what mode. For example, how would I know which bass notes to play in a 1-7-3-6-2-5-1 progression? So far, all I have heard is play the 3rd or the 5th. Do you have any other courses explaining this type of bass note accompaniment or theory?

Students get understandably confused when we talk about modes, degrees of the scale, Roman numeral analysis (ie, harmonic progressions), and chord tones. Here, we will try to put all of that confusion to rest.

Modes = scales. “Modes of the major scale” refers to the 7 different modes/scales that we can create by starting a scale on each note of the major scale. Having 7 notes of a major scale means we have 7 modes that can be created from a major scale. (Ex: The notes of a C major scale = C, D, E, F, G, A, B. If we start a scale on C and play the notes C, D, E, F, G, A, B, C, we get a “C Ionian scale.” If we start a scale on D and play the notes D, E, F, G, A, B, C, D, we get a “D Dorian scale.” If we start a scale on E and play the notes E, F, G, A, B, C, D, E, we get an “E Phrygian scale.” And so on.

Degrees of the scale = the individual notes that make up a scale in the order in which they appear when playing the notes of the scale in ascending order. Take an F major scale and play the notes in ascending order = F, G, A, Bb, C, D, E, F. The first note you play (“F”) is the “1st degree of the scale.” The fourth note you play (“Bb”) is the “4th degree of the scale.” And so on.

Roman numeral analysis = the Roman numerals musicians use to communicate harmonic progressions. “Harmonic progressions” is just a fancy way of saying “the order in which the chords happen.” So if I said something like “the harmonic progression is I, vi, ii, V in the key of E major,” that would be translated as “the chords are E major, C# minor, F# minor, and B major.” Notice the similarity between Roman numerals and scale degrees. Both indicate a note’s order of appearance in the scale, but scale degrees refer to a particular NOTE in the scale; Roman numerals refer to a particular CHORD that is built on that scale degree. Remember also that scale degrees are spelled with a regular number (ie, “5th” degree of the scale), and Roman numerals use upper-case if major/dominant, lower-case if minor/diminished (ie, the “V” chord in the key of C is a G major chord. The “ii” chord in the key of A major is a B minor chord).

Chord tones = particular notes of a chord. And those particular notes are the root (or 1st scale degree), the 3rd, and the 5th. If the chord is a 7th chord, the 7th scale degree is also a chord tone.

Let’s get back to the student’s question. “Bass notes” can refer to anything you choose to play in the bass register (ie, left hand) and doesn’t specifically refer to any mode or scale. When asking “which bass notes to play in a 1-7-3-6-2-5-1 progression,” I see a couple issues that I need to correct. I would first need to know in which key we are playing in order to answer this question. Secondly, the progression (even though I know exactly what the student means) is technically incorrect because he used regular numbers (which refer to scale degrees) and should have used Roman numerals (which refer to chords).

So let’s plug in some information. If we are in the key of G major, which has a key signature of 1 sharp (F#), then I would answer by saying “the bass notes of a I-vii-iii-vi-ii-V-I progression in the key of G major would be G, F#, B, E, A, D, G.” Are you able to see what I did there? First, I referred to a specific key (G major) because otherwise the harmonic progression has no context. Scale degrees and Roman numerals must refer to a specific key, otherwise they are merely a formula that could apply to any key. Secondly, I changed the regular numbers to Roman numerals because I know what’s really being asked is “what are the bass notes that would correspond to these CHORDS.” One other little thing I did was to use upper-case or lower-case Roman numerals depending on whether the chord indicated is a major or minor/diminished chord.

Now, one last piece of information to bring this all full circle. What are the CHORDS in the above progression? Answer = The chords in a I-vii-iii-vi-ii-V-I progression in the key of G major are: G major, F# diminished, B minor, E minor, A minor, D major, G major. Now maybe what the student was trying to ask is “What are the modes that correspond with these chords?” Ahhh, well that’s a question that introduces a new term – chord scales.

– are scales which contain the notes necessary for creating a particular chord and, in the jazz world especially, improvising over that chord. If I encounter an A minor chord and want to improvise over that chord, I might first want to know which scale would work over A minor. The answer will be a chord scale which contains all of the notes that make up an A minor chord (i.e., the chord tones of A minor) and also fits into the key in which I’m playing. So, if I’m playing in the key of G major and I encounter an A minor chord, I want to find a scale that has all of the chord tones of A minor and fits in the key of G major (i.e., does not use notes outside of the G major key signature). The answer would be a scale which uses the following notes – A, B, C, D, E, F#, G, A. But what is this chord scale called? An “A dorian scale.”

Here’s a little twist on that question. What if I encounter an A minor chord while playing in the key of F major? What chord scale should I use to improvise over A minor in this instance? The answer is a chord scale that uses the notes A, Bb, C, D, E, F, G, A – all of the notes of an A minor chord, and also only notes contained in the key of F major. What chord scale is this? It’s an “A phrygian scale.” I hope you’re starting to understand this relationship between chord scales and modes. It’s certainly a little confusing at first, but actually somewhat easy once you get all the music lingo straight.

As always, happy practicing!

  • This article really lays it out well. The 2nd half was most interesting to me. I’m usually improvising over the chords with an enclosure pattern, 1 whole step scale tone above the target & a chromatic non-scale tone below the target. But am starting more to add in the modes & trying to target the next chord scale tone as I progress, hopefully a 3rd or root.

  • Edilberto says:

    The explanation is a lesson in itself. Thank you for the explanation as I am likewise enlightened. This hobby seens to be a never ending study.

  • Ehab says:

    I”m a little confused in the last paragraph. is Bb a note in the A minor chord? I get we’re in the key of F major and it’s called the “A phyrigian scale” but confused by the statement that it’s part of “all the notes of an A minor chord”. if we were in the key of C would that still be true?

    • Steve says:

      I am also confused by this. I should say it’s a typo. If not, there’s something deeper that I haven’t grasped yet.

  • Ralph Sirvent says:

    I was taught that modes have no sharps or flats. They are all built on the natural scale of the piano. You referred to the F Major scale as A Phrygian. Phrygian is a mode but is also the F Major scale? Please clarify this for us.

    • Jeff says:

      Hi, Ralph. I will take a stab at clarifying this for you. The first point to realize is that when you name a scale you are really just applying a shorthand term for a particular sequence of whole steps and half steps. For example, the major scale–also known as the Ionian mode–has two whole steps, a half step, two more whole steps and then a half step. Each of the other modes has it’s own particular sequence of whole and half steps.

      The second point is that any type of scale–major, minor, phrygian mode, etc.–can start on any of the 12 different tones. All that matters is that when you play the scale you follow the particular sequence of whole and half steps that define that scale. So, we have twelve major scales, twelve natural minor scales, etc. The same is true for the modes. For example, the Ionian mode is just a fancy term for the major scale. If we start it on a C it has no sharps or flats (C-D-E-F-G-A-B-C), but if we start on an F it will have a B-flat (F-G-A-B-flat-C-D-E-F). Take the phyrigian mode as another example. Incidentally, this is the scale you make if you start on the 3rd tone of a major scale and go up from there using the tones of that major scale. So, If we start it on an E (the 3rd tone of C-Major) then like the C-Major scale it has no sharps or flats (E-F-G-A-B-C-D-E). It differs from the C-major scale only in its starting and end points. But if we start it on an A–the 3rd tone of the F-major scale–then, like the F-major scale it will have a B-flat (A-B-flat-C-D-E-F-G-A).
      So, it is not the case that modes have no sharps or flats, for that depends on which mode you are playing and which tone you start on. So, why were you taught that they have no sharps or flats? Probably because when you learn the modes the easiest way is to use the C-major scale as your reference. So, when you learn the Dorian mode you learn that it’s the scale you get when you start on D and go up with no sharps or flats. Another way you could have been taught it, however, is that it’s the scale you get when you start on the second tone of ANY particular major scale then play all the notes of that major scale. This would have avoided the confusion. Similarly the Phyrigian mode is the scale you get when you start on the 3rd tone of any major scale and go up using the notes of that major scale. If you are using C-major as your reference, then you could say the Phrygian mode is the scale you get when you start on E and go up with no sharps or flats. But you could use any other major scale as your reference. In the article, Willie uses the F-Major as the reference. So, if you want to use the tones of the F-Major scale to play a Phrygian mode then you start on A–the 3rd tone of that scale–and go up using the tones of the F-major scale. So, the F-major scale is not exactly the A-Phryigian mode. They use the same tones, but have different starting/ending points.
      I hope that makes it clearer. Sorry for wasting your time if it didn’t!

  • Doug says:

    This was a great article Willie and timed perfectly. I am about a third the way through the Music Theory course and am learning much from it. It is a great course and I recommend it to all of you that want to grow as a musician.

  • jim devenny says:

    Great lesson in itself, but would appreciate comment on the question asked, namely what left hand bass notes to play (other than just the root of the respective chords)?

  • Gary says:

    A million thanks for this one Willie!

    –Gary

  • Emmanuel says:

    Hi.this is fantastic willie thanks for clarification

  • Peter says:

    Referring to your example of A minor chord played in the key of F major, it is not exactly clear to me whether the notes that can be used for improvising are:

    1) those notes that are notes of BOTH the A minor chord AND the F major key, in which case it would just be the notes of the A minor chord, which does not make good sense, or

    2) those notes that are notes of EITHER the A minor chord OR the F major key, in which it would just be the notes of the F major chord, which makes better sense and is a better way of expressing what you wanted to say.

    Please comment if my above understanding is correct.