New to music theory, am I right?

[Area 39]

Hello all.

I've recently started learning the basic scales and modes and I've had a go at working something purchasing my new knowledge, but I'd like to know if I'm right?

I have a guitar based track with a tonal centre of D major with C major and G major appearing in the chorus, I have a main guitar riff using D, E, F#, G and A but I also have a bass line using the same notes as the riff with the addition of a C note.

So, if I'm right that everything revolves around D and the 3 Major chords and the C note in the bass line, does this all point to D Mixolydian?

[BJG145]

I think so, kind of. I mean, the notes of D mixolydian fit with the three chords and the riff.

D – E – F# – G – A – B – C

If you strum D/C/G and hum the scale, the characteristic C sounds OK over the D chord (minor 7th) and C (root), but it grates a bit over the G (4th). I mean, you wouldn't want to dwell on it; it needs to resolve.

So, does it work as a theoretical construct - yes. Is it helpful as a songwriting aid over these chords...maybe. You wouldn't want to be limited by it.

(Disclaimer: I don't know much about music theory.)

[RichardT]

Basically yes!

[BWC]

Yes, a minor seventh (C in this case) in a major key is what Mixolydian is all about.

Here's one way to think of it:
Ionian = Natural Major
Lydian = Natural Major with a ♯4
Mixolydian = Natural Major with a ♭7

Aeolean = Natural Minor
Dorian = Natural Minor with a ♯6
Phrygian = Natural Minor with a ♭2

Locrian = Diminished

Context matters though. From your description, it could also be just a key change for the chorus.

[Area 39]

Thank you for the replies.

[GilesAnt]

Context very much matters. Based on the notes and chords you specify it could also simply be in G major, but without seeing/hearing it is hard to say.

[MOF]

Context very much matters. Based on the notes and chords you specify it could also simply be in G major, but without seeing/hearing it is hard to say.

Also there is such a thing as ‘passing notes’ which strictly speaking don’t affect the chord.

[Ben Asaro]

I agree with GilesAnt, it is probably in GMaj, not D Mixolydian. Without hearing the piece in question, or seeing the arrangement, there’s not enough context to be 100% sure, but it sounds like you are playing in GMaj.

The two things that’s will determine the key center or mode you are playing are:

What feels like ‘home’? Does it satisfy the feel for Mixolydian? Mixolydian is a major scale with a flattened 7th. So a progression in D Mixolydian would feature the flat C a lot more, perhaps starting on D7 then CMaj.

You also mentioned the notes E, F#, and G but not the actual chords.

So it could also be viewed as DMaj with a flat 7 passing tone.

[Wurlitzer]

The first thing the OP mentioned was the "tonal centre of D" so it's clear that he's hearing the song based around that. As such, D mixolydian is an accurate description.

It's worth noting that this set of chords - I, IV and bVII (here D, G and C) is extremely common. EG Norwegian Wood or the coda to Hey Jude; Jesus Christ Superstar; or practically anything by ACDC. So much so it's hardly even worth worrying about the C as anything remarkable. "Mixolydian" is a fancy term belonging to medieval modal theory, but this basic scale - like the major scale but with a flattened 7th - is ubiquitous in rock music.

[Ben Asaro]

The first thing the OP mentioned was the "tonal centre of D" so it's clear that he's hearing the song based around that. As such, D mixolydian is an accurate description.

It's worth noting that this set of chords - I, IV and bVII (here D, G and C) is extremely common. EG Norwegian Wood or the coda to Hey Jude; Jesus Christ Superstar; or practically anything by ACDC. So much so it's hardly even worth worrying about the C as anything remarkable. "Mixolydian" is a fancy term belonging to medieval modal theory, but this basic scale - like the major scale but with a flattened 7th - is ubiquitous in rock music.

Agree to disagree on this.

[BWC]

The first thing the OP mentioned was the "tonal centre of D" so it's clear that he's hearing the song based around that. As such, D mixolydian is an accurate description.

It's worth noting that this set of chords - I, IV and bVII (here D, G and C) is extremely common. EG Norwegian Wood or the coda to Hey Jude; Jesus Christ Superstar; or practically anything by ACDC. So much so it's hardly even worth worrying about the C as anything remarkable. "Mixolydian" is a fancy term belonging to medieval modal theory, but this basic scale - like the major scale but with a flattened 7th - is ubiquitous in rock music.

Agree to disagree on this.

I also caught that the OP mentioned a "tonal centre of D," and that could be accurate. I still maintain, though, that we need more info about the context to be able to say for sure.

Mixolydian is indeed very common in rock, and especially in country music, but that it's common, doesn't change what it is, nor make it any less worthy of noting and understanding. And I don't think there's any thing "fancy" about the term; that's just what it's called. I suppose we could call it the V7, if you'd prefer.

[GilesAnt]

we need more info about the context to be able to say for sure.

Exactly. We can't take the OP opinion as definitive that there is a tonal centre of D major. This could be a dominant preparation for the tonic of G. Not all music starts on its tonic.

It could alternatively be D mixolydian - as Wurlitzer says, this mode (flattened 7th) is common in rock music (which this may or may not be).

You need to see or hear the music to really decide - even then people can disagree.

[Wurlitzer]

The question of whether D or G is the tonal centre is simply resolved by (a) what note the melody resolves onto and sounds finished on (and, usually, actually finishes on), and (b) the relationship of the chords to the phrasing. Your ear, sense of melodic impulse and awareness of where phrases are "arriving" tell you immediately whether a chord progression of D - G is I - IV in D or V - I in G.

The OP has said it's in D, so those factors are clearly adding up to that, for him, which is good enough for me. As he wrote the song and decided how and when each phrase resolves, I can't imagine why he would be wrong. In fact I can't see how he even theoretically could be wrong. If he's feeling it in D as he writes it, then it's in D. The only question is what exactly it's doing around D.

But sure, listening to it or seeing a score would resolve the question for those who believe theory is something to be externally imposed upon the compositional process, rather than something to illuminate it from within.

[GilesAnt]

Since the OP is uncertain about the key/modality of his music, we can't assume he is right about the tonal centre of D at the beginning - does he simply mean a chord of D or a whole passage containing other chords as well?. If he knew, he wouldn't be asking.

It's not particularly a question of deep theory, it's just that given what he has told us there are two leading possibilities.

Incidentally, the melody is not necessarily the best guide to establishing key, since a given note may be part of many chords. A melody may be harmonised in different ways after all. Many composers actually exploit this ambiguity of keys and tonal centres to challenge the ear. Hence there is not always a 'right' answer.