chords as Roman numerals

[donn]

Chords can be called out as Roman numerals. This is common knowledge to most or all of you, as far as I know. But after using this notation here, it occurred to me that you never know for sure, and it wouldn't hurt to just go over it once in case anyone was wondering what that was about. Feel free to make corrections, I have only a cursory acquaintance with the subject myself.

The idea is that, given a specific key, for each note in the scale there's one major or minor chord whose root is that note, and whose other notes are in the scale. Therefore if we want to talk about chord progressions independently of the key, we can just use the scale degree for the name of the chord, expressed as a Roman numeral. Like "IV", instead of "F, fer example if ye's playin in the key of C". I read that we're supposed to use lower case for minor chords, but I'm not sure that's universal -- I would assume minor for II and VI, lower case or not.

I tend to learn music by reflex and have minimal acquaintance with theory, but this notation seems especially useful now that I'm playing the accordion, I guess since the chords are laid out in this way that really makes it easy to think about them independently of key.

 

[Daveg4otu]

I agree to a large extent with what you're saying.
As a guitarist I have always tended to think in terms of the I.IIm, IV,V7,VIm and to just move everything up and down the fretboard to accomodate key changing. Using that method of notation has the added benefit that a tune backing can be written in a totally keyless manner.

 

[donn]

Indeed, I've noticed that practice particularly among jazz musicians etc. Honestly, I don't use it so much myself, and when someone kindly offers some numbers by way of informing me about the upcoming tune, it really doesn't mean a thing. I have been playing (bass, etc.) totally by ear for all these years, and just recently thanks to the accordion I'm starting to become better acquainted with the system ... but still not well enough to play from that notation, I just use it infrequently in a more discursive context. And I didn't intend to promote it for any particular purpose, just to explain in case the Roman numerals may have mystified anyone.

 

[jarvo]

Lets see if I have it half right. :roll:

My understanding is that the numerals follow the scale of the key and then can be used to indictate the order in which chords appear....the chord progression.......based on a set principle that the key of C Major will have the position I as C maj...then the chords will follow in a laid out progression at II,III,IV etc. following the key of the scale............us Bluesists tend to stick to the I ,IV,V with 7ths and minor variations us nasty little three chord trickers .... so in C that would be C whatever, F and G whatever....7s or minors for a bit of variety....Since I have been going to a jazz Club near here I have rediscovered theory that I had left behind and am learning some new stuff :tup: ....as well as that not all musoes are nice people ! :tdown:

However I am with Donn on this ,somebody saying that it is a I,V ,VII etc progression is absolutely useless if you don't know what key it's in....and then if you don't know that scale either that's not much better....just shout out the freaking chords you intellectual snob you :lol: :hb :lol:

 

[donn]

I find no error in your summary. Another `whatever', for me, is the III chord, for me usually a 7 but sometimes minor; I suspect there may be some connection to harmonic vs. melodic minor, but lack the theoretical sophistication to nail that down. No big deal. And then there's a sort of Slavic system that seems to be short one, like II is missing. As for calling out chords -- I would be in a better position to complain about I-V-VII, if the freaking chords would do me all that much more good. When I said I play by ear, I meant it. Don't talk to me while I'm playing.

 

[Daveg4otu]

<HIGHLIGHT highlight="#ffff00">[highlight=#ffff00]us Bluesists tend to stick to the I ,IV,V with 7ths and minor variations us nasty little three chord trickers[/highlight]</HIGHLIGHT>

Nice to know I'm not on my own.

All seems so simple when you have grown up with it(the 3 chord trick/12 bar blues etc)- yet trying to get the message across can be difficult.

I spent yesterday evening with friend who is an aspiring guitarist....but he doesn't understand any musical theory(and really doesn't want to) - not even the 3 chord trick altho' he can stagger through a few tunes by ear.Been trying to teach him really basic 12 bar blues(think :Guitar boogie shuffle etc.) for weeks now and still he doesn't see it...I may have to resort to torture before long!
:evil:

Whatever - all good fun.

 

[dan]

Old thread, but one of few subjects where I know enough to contribute. I agree that shouting out the numbers at a session is of limited practical value. Feeling the numbers in the left hand, however, can be useful for ear training, improvisation, and song writing.

Here’s an exercise to reveal the relationship between key signatures and chord progressions. Get an oompah or waltz rhythm going in the left hand: C major, F major, G7, C. Fit the C major scale in the right hand over that left hand rhythm. Now transpose the I-IV-V-I pattern to G. G major, C major, D7, G major. Notice how moving your key center up a row on the button board adds a sharp to the key signature. Moving down a row flattens a sharp or adds a flat to the key signature. Now you’re ready for a jump up three rows to the relative minor. The key of G is good for starting out because you can use the rhinestone or marking on E to help you gauge the distance. GM, CM, D7, GM, Em, Am, Bm, Em. Repeat. Notice that you can use the notes of the G major (or E natural minor) scale to noodle over these chords because they’re all constructed from the notes of that scale. Diatonic harmony in a nutshell, built into the Stradella bass system: bottom to top you have IV- I – V- ii- vi-iii.

Plenty of popular and folk songs use only those chords, particularly vi V I and IV. Practice singing simple songs while picking out the harmony by ear on your left hand and you’ll start to recognize the sound of a IV chord versus the unfinished sound of a V chord, and match that sound to the muscle memory “down 1 from the key center” on Stradella bass.

Plenty of songs depart from those harmonies. If you’re aware of it when it happens, you can be on the lookout for accidentals. Western music is all about the movement from the dissonant dominant seventh to a stable tonic, and a common trick is to modify another chord into a dominant seventh to get that same tension and release. Instead of Am, D7, G, we play A7, D7, G, possibly introducing a C# accidental to the melody. Instead of Em, Am, Bm, Em we play Em, Am, B7, Em, introducing a D# accidental to the E minor scale (harmonic minor) and maybe also a C# (melodic minor).

I’m not sure how the theorists approach modes, but I like to think of it as a variation on that same pattern. The "Amelie" chord progression of Dm Am F C are all chords that could be played under C major, but by starting on and returning to ii, we make it D dorian. G7 is avoided because it wants to resolve to C.

Cheers

Dan

 

[TomBR]

I think chord numbers are a very useful framework for building understanding of whats going on harmonically.
The concept has been developed into the Nashville Numbers system
https://en.wikipedia.org/wiki/Nashville_number_system

Its interesting to see an arrangement of a song laid out for a professional session musician using the system, heres one with explanation.
http://www.harmonycentral.com/articles/crunching-the-nashville-number-system[/url]

 

[acordiansam]

One of the main reasons the write like that is so no matter what key the singer at that time needs to sing it in. Also when you start adding horns and wood winds they all have different notation and key signatures. Not just bass and treble clef. If you plan on jamming in bands it's well worth the time to learn. Even if you play by ear.

 

[losthobos]

Definetly worth learning the numbers notation system...you will see so many similarities between progressions/tunes that after a while it makes them easier to recognise by ear whatever the key.... get a chromatic accordion and you're halfway to the bank....
I tend to write out new tune charts with both methods till they are locked in my head...
may be likened to the continental do,fa,so way of teaching music rather than just being key specific....

 

[losthobos]

Just pedalling back from town and it hit me...the numerical system is a giveaway fir accordion given the layout of the stradella system....moving floor to chin you have 1/5/2/6 moving down you have 1/4/dom7....what more do you need to know...get this nailed on the left hand and the guidelines fir the right will be in your ears....genius whoever invented stradella

 

[BobM]

moving up floor to chin you have 1/5/2/6 moving down you have 1/4/dom7....what more do you need to know.

Not as degrees of a scale though, i.e. maj, min, min, maj etc..

 

[dan]

moving up floor to chin you have 1/5/2/6 moving down you have 1/4/dom7....what more do you need to know.

Not as degrees of a scale though, i.e. maj, min, min, maj etc..[/quote]

Right, so you have to practice the pattern. I like to run a vi-ii-V-I and a IV-V-I in the left hand with scales in the right to get my ears and fingers comfortable with a given key before I play a tune.
C major/A minor. C Am Dm G7 C. C F G7 C. Am Dm E7 Am.
D major/B minor: D Bm Em A7 D. D G A7 D. Bm Em F#7 Bm.
etc.

Disclaimer: Using this technique, I can improvise reasonably well and pick up simple tunes by ear, but am awful in every other respect.

 

[Ganza]

us Bluesists tend to stick to the I ,IV,V with 7ths and minor variations us nasty little three chord trickers

Nice to know Im not on my own.

All seems so simple when you have grown up with it(the 3 chord trick/12 bar blues etc)- yet trying to get the message across can be difficult.

I spent yesterday evening with friend who is an aspiring guitarist....but he doesnt understand any musical theory(and really doesnt want to) - not even the 3 chord trick altho he can stagger through a few tunes by ear.Been trying to teach him really basic 12 bar blues(think :Guitar boogie shuffle etc.) for weeks now and still he doesnt see it...I may have to resort to torture before long!
:evil:

Whatever - all good fun.


The standard progression for samba is: I, VI7, IIm, V7.

So for D, it would be: D, B7, Em, A7.

Brazilian chords are often extended, so it could be something like: D9, B7, Em6, A713

Sometimes they substitute the second in the sequence with a Dim. e.g. D, Fdim, Em, A7

 

[JeffJetton]

Yes, as mentioned, here in Nashville we refer to chords by their number all the time, and will write entire chord charts using just numbers. It's very handy, and has the delightful side-effect of training your ears to hear chord changes better and better, the more and more you play from (and transcribe) such charts.

A few key differences between the "Nashville Number System" and the sort of harmonic analysis we're talking about in the bulk of this thread:

• Arabic numerals are used rather than roman numerals. So we'd use 4 instead of IV, 5 instead of IV, etc.
• All chords are major unless specified otherwise. So if you see just a "3", you'd play a III major chord (even though III chords of major keys are diatonically minor).
• Minor chords are marked with a minus sign, a la jazz charts.
• Chords are simply marked based on scale degree, with no concern about their harmonic function. For example, if the chords are D7 to G7 to C, that D7 is really functioning as a secondary dominant and would be considered a V7/V chord in the purest sense. But we just slap a "2" on it anyway like a bunch of barbarians.

I always try to introduce some basic numerical chord concepts to my students as we go along. Such as:

• If you're on a row in the left hand that corresponds to the key of the song, that's the I chord.
• If you go "upstairs one floor" from that row, you will always be on the V chord ("high 5")
• If you go "downstairs" instead, that's always on the IV chord ("4 towards the floor")

Then I'll point out things such as how V chords are frequently dominant seventh chords, about how anytime a piece of music has you play a dom7 chord it will almost always resolve down one row to its relative I chord, and how V chords will often be the chord where the bass pattern is "flip flopped" (alternate bass is played first).

 

[donn]

Thank heavens for barbarians! I think though that many of us who speak the roman-numeral dialect might do the same thing, it's just a question of distinguishing a major* II from the expected minor. I would be sorry to encounter anyone so attached to whatever theoretical purity as to call both D and G "V", if indeed theory would call for that, have no idea.

[*More commonly 7, but in the English tunes that are mostly what I play in public, it would be plain major triads.]
[**though to be sure, we'd just play everything in G and wouldn't need movable notation.]

 

[JeffJetton]

I would be sorry to encounter anyone so attached to whatever theoretical purity as to call both D and G V, if indeed theory would call for that, have no idea.

Well, to clarify, the D7 wouldnt also be a V7, but rather a V7/V. Essentially, a five chord of the five chord or secondary dominant. It communicates the fact that the song has switched there from its home key of C major to a temporary key center or key of the moment of G major. The D7 is acting as the V7 of that new, brief key. Which explains the F# in the D7 chord... its borrowed from the G major.

All fairly useless knowledge when youre banging along with the song in a beer-soaked honky-tonk, of course. So we just call it a 2.

(But it does bring up a good reason why number charts are rarely used in jazz.)