#1
I have a great song in key of F major I'm working on. If I got the theory right, the chords are F Maj, Gm, Am, Bb Maj, C7, Dm, and Em7b5.

The progression, taken right off the sheet music:
{F Maj - Cm - Bb Maj} x 3 {F Maj - Ab Maj - Bb Maj} x 1

Observations: The fifth is a dominant chord, made into a minor chord. Ab Maj subbed for Cm. While Ab Major not in the key of F Major, Ab Maj shares two notes with Cm; the C and Eb.
Why do the chords Cm and Ab Maj "work" in the key of F Major??
#2
1) You may be in Bb, which would explain the Cm. But that depends on the rhythm as much as the chords themselves. The first chord isn't always the tonic.

2) The Ab is still non-diatonic in Bb, but basically the answer is that it works exactly because of what you noted: many of the notes overlap, and so they want to resolve similarly.


VVV Technical Nerd Stuff VVVV

This "trick" is called key borrowing. You borrowed a chord from different key in order to create an interesting sound that doesn't lead away from the home key. In this case, it allows you to resolve the bass voice to Bb stepwise from both directions - first descending a whole step (Cm-Bb) and then ascending a whole step (Ab-Bb). The bVII I resolution is an easy way of getting stepwise resolution without the stuffy, overly traditional sound of resolving scale degree 7 to 1.

So in this circumstance, you aren't using a substitution. A substitution is tied up a bit more in voice leading principles than key borrowing is. In a proper substitution, the root is somewhat ambiguous because you can analyze the voicing as root position of one or inversion of the other. For example, C7b5 resolves to F, but if you put that b5 in the bass, it spells a root position Gb 7b5, which is the classic triton substitution you hear about in jazz (rough equivalent of a Neapolitan 6th in classical music).
Last edited by cdgraves at Oct 10, 2015,
#3
Do you have a ink to the song?

Just by looking at the chords, it's pretty hard to tell the key (at least in this case). We need to hear the song. If it's in F major, the Ab major would be a bIII chord, borrowed from the parallel minor. That's really common. Well, the same applies to the Cm chord - you could say the b7 scale degree is borrowed from the parallel minor. Well, where it's borrowed from doesn't really matter. It's called modal mixture.


When you listen to the song, which of the chords feels like home? That's also your key.
Quote by AlanHB
Just remember that there are no boring scales, just boring players.

Gear

Bach Stradivarius 37G
Charvel So Cal
Fender Dimension Bass
Hartke HyDrive 210c
Ibanez BL70
Laney VC30
Tokai TB48
Yamaha FG720S-12
Yamaha P115
#4
Thank you for your responses! After reading Rick Roseberry's "Secrets of Chord Substitutions Revealed", I was overwhelmed. Nothing mentioned about "key borrowing" or parallel minor. I have a long way to go in understanding harmonies. "Broken Together" by Casting Crowns starts on F Maj, but indeed it might be a more Bb tonality, not sure. Most I know with one year of playing guitar like me just want to play songs, that's ok, but I want to know why - someday write my own stuff, and get more involved than I vi IV V I.

https://ia802703.us.archive.org/27/items/SecretsOfChordSubsRevealed/SecretsOfChordSubsRevealed_print.pdf
#5
I am breaking my UG fast for this post and this alone, then I'm gone until next Friday night or Saturday morning.

No, it's in F. Actually, it borrows so much that it does sound like F Mixolydian (which would understandably have the Bb accidentals). The Ab is the only off-key chord, then... think of it as tone coloring. The melody is all in F Mixolydian, but the Ab is borrowed from minor.
Glad to cross paths with you on this adventure called life
Quote by Jet Penguin
lots of flirting with the other key without confirming. JUST LIKE THEIR LOVE IN THE MOVIE OH DAMN.
Quote by Hail
you're acting like you have perfect pitch or something
#6
Quote by dougp_abo
Thank you for your responses! After reading Rick Roseberry's "Secrets of Chord Substitutions Revealed", I was overwhelmed. Nothing mentioned about "key borrowing" or parallel minor. I have a long way to go in understanding harmonies. "Broken Together" by Casting Crowns starts on F Maj, but indeed it might be a more Bb tonality, not sure. Most I know with one year of playing guitar like me just want to play songs, that's ok, but I want to know why - someday write my own stuff, and get more involved than I vi IV V I.

https://ia802703.us.archive.org/27/items/SecretsOfChordSubsRevealed/SecretsOfChordSubsRevealed_print.pdf

Borrowing from the parallel key is the most common explanation for non-diatonic chords in pop music.

I wouldn't recommend reading a book with random "rules" without any real life examples. Yes, I'm sure everything listed in that book is usable information, but I would not recommend starting with learning some "rules". Start with actual music. Also, that book has more application to jazz than anything else.

First learn about keys and chord functions. We aren't necessarily always talking about chord substitutions when there are non-diatonic chords. Sometimes that applies, many times it doesn't.

Start with actual music. I don't like books that just list some "rules". I don't like chord books that just show 1000 different voicings of different chords. That's really not informative. Or it can be if you know exactly what you are looking for. But for example in your case you didn't actually know what you were looking for, and reading this kind of book just confuses you.

If you want to know more about non-diatonic chords, look at modal mixture and secondary dominants. That's really pretty much all you need to know, and you can explain almost any non-diatonic chord (at least in pop music).


And yeah, that song is in F. I'm not sure about the "mixolydian" explanation. It also uses the normal V chord in the chorus. I would just say it's in F major, you could say it borrows from mixolydian or whatever (or parallel minor). The verse does have a mixolydian sound to it.
Quote by AlanHB
Just remember that there are no boring scales, just boring players.

Gear

Bach Stradivarius 37G
Charvel So Cal
Fender Dimension Bass
Hartke HyDrive 210c
Ibanez BL70
Laney VC30
Tokai TB48
Yamaha FG720S-12
Yamaha P115
Last edited by MaggaraMarine at Oct 11, 2015,
#7
Quote by dougp_abo
I have a great song in key of F major I'm working on. If I got the theory right, the chords are F Maj, Gm, Am, Bb Maj, C7, Dm, and Em7b5.
You're making a very common (and quite natural) mistake here: learning some basic theory and then expecting those "rules" to apply to any song you come across.

The point about theory is it's only "common practice", and the concept of the diatonic major key (as you've spelled out correctly) is only the most basic common practice; chapter 1 of the book, if you like. Theory books have to start somewhere, so they start simple. But there's a whole load more common practices to learn about. Not necessarily more complicated, just more potential ingredients for the mix.

As mentioned above, one of the most common practices in rock music is the notion of "mode mixture", often expressed as "borrowing from the parallel minor" - because it's usually most noticeable as alterations to (what seems to be) major key.
Remember this is not breaking rules: it's following rules.
The main rule, of course, is: "if it sounds good, it's correct."
What sounds "good" tends to be what sounds familiar, so rock composers tend to copy what other rock songs do, without necessarily knowing anything about theory. All the rules they (we, you!) need to know are expressed in songs. Books are irrelevant. (If you mention "mode mixture" or "borrowing from the parallel minor" to the average rock composer, they'll probably give you a "huh?" look.)

It's as if rock recognises no real distinction between major and minor keys, other than their tonic chord.
Start and end on a major chord, the key is major.
Start and end on a minor chord, the key is minor.
Any other chords used may come from either of those parallel scales: major or natural minor, which (speaking modally) includes mixolydian and dorian. Mixolydian and dorian don't give any chords that aren't provided by Ionian and aeolian, so we only need to consider ionian (major scale) and parallel aeolian (natural minor) when compiling the available chords. (Chords can also be borrowed from parallel lydian and phrygian, but that's a little rarer.)

So, in key of F, as well as the "vanilla" chords from F major (as you've listed), you will find in common use Ab, Eb, Db and Bbm (all from F minor). I.e., bIII, bVII, bVI, minor iv. (bVII being the most common.)
The vii chord of F major (Edim or Em7b5) you will probably never find! Any chord in F major with an E bass is more likely to be C/E, C7/E, or Am/E (or even Fmaj7/E. And Eb is probably going to be more common anyway.
If you do ever see Em7b5, it's probably going to be ii in D minor - leading to A7 and then Dm. This is extremely common in jazz, but still pretty rare in rock.

If your "F major" key contains no C major, but either Eb or Cm (as here) then you could describe it as "F mixolydian" if you like (as mentioned above). Cm is actually fairly rare in key of F. (Even in key of F minor, C major or C7 is more common.)

BTW, the pre-chorus and chorus of this song contains other interesting changes:
||Ab6(Fm7/Ab) - |Gm7 - |Ab6 - |Ebmaj7 - |
|F - |C - |Eb(add9) - |Bbmaj7 - |
|F - |C - |Eb(add9) - |Bbmaj7 - |
|Gm Fmaj7/A |Ebmaj7 - || (F...)
What sounds like the key centre there? And does it really matter anyway? (Sounds resolved on that first Eb to my ears; but then it's more like Bb in the next couple of lines.)
All that really matters - the rule that needs to be followed - is that the changes sound logical, that each pair of chords has a familiar relationship (usually sharing a scale); and (of course) that they harmonise the melody well, and that the melody remains singable.

It's probably true that the diatonic major key - the old "do re mi" - still sounds to our ears like a "natural" musical entity, a basic foundation (it's not really "natural", just a long-standing cultural standard). So we hear chromatic chords and borrowed chords as "different" in some way - but such deviations are so common that they are equally "right-sounding". We hear a key centre (usually) but accept that all kinds of flexibility attaches to that. We don't even mind if a key centre is ambiguous (which I think it is here, at times), as long as chords don't chop around too unpredictably; and these are really very familiar changes.
#8
To me F sounds like the key center throughout the song.

The F-C-Eb-Bb in the chorus is a pretty common progression (I-V-bVII-IV). Notice the chromatic line F-E-Eb-D that you get from the chord tones.

Oh, the main progression (I-v-IV) is also used in "Learn to Fly" by Foo Fighters.
Quote by AlanHB
Just remember that there are no boring scales, just boring players.

Gear

Bach Stradivarius 37G
Charvel So Cal
Fender Dimension Bass
Hartke HyDrive 210c
Ibanez BL70
Laney VC30
Tokai TB48
Yamaha FG720S-12
Yamaha P115
Last edited by MaggaraMarine at Oct 11, 2015,
#9
Good stuff here. Just want to point out the presence of a IV-I plagal cadence between Bb and F. We aren't in anything modal. We have a I-Vm-IV, and a I-bIII-IV.

As others have pointed out, you can borrow chords from parallel modes. In this case, the Cm and Ab are borrowed from F natural minor.
"There are two styles of music. Good music and bad music." -Duke Ellington

"If you really think about it, the guitar is a pointless instrument." - Robert Fripp