Forum: music.stackexchange.com
Tags: <theory><harmony>
Title: Roman Numerals for minor chord progression E.g. Am F C G
Question: Quick question,  Take the progression Am F C G   Would the correct way of writing this in Roman Numerals be   i VI III VII   Or  vi IV I V  Thanks

Answers:
sents: text: ...Take the progression Am
text: F C G
text: That list of chords doesn't determine a key.
text: Those chords as a bunch of tones could match the key signatures of A minor or C major... or you could even say it's in F where the G chord is a secondary chord, etc.
text: etc.
text: The real point of putting Roman numerals on the chords it to say what key the chord are in!
text: IMO it's more important to say what the key is than exactly which chords are used, because key structure is paramount in understanding compositional form.
text: Put a key label with the Roman numerals...
text: Am:
text: i VI III VII or C: vi IV I V
text: However, you need to consider one other important point.
text: The traditional way to define a key is with a dominant chord , and the clearest way to do it is a progression from a dominant to tonic chord.
text: So, you would want either Am: V I or C: V I somewhere in the music to make a clear case for a key actually being established.
text: If you don't establish a key with a dominant to tonic the music can be described as non-functional harmony .
text: That sounds bad, but it isn't.
text: It's simply a harmonic description.
text: Lots of pop & rock music is non-functional.
text: But, when the harmony is non-functional - lacking a clearly defined key - it sort of become irrelevant which Roman numeral labels you use.
answer_details: author: music.stackexchange.com/users/23919/Michael Curtis
score: 2
sents: text: My rule of thumb is: is the tonal centre of the song Am ?
text: Stick to i VI III VII .
text: Does the song start in the relative major key for instance ( C in this case), then feature this passage?
text: Then stick to vi IV
text: I V .
text: See Hallelujah by Leonard Cohen , the verse is in the major key (starts with the I/vi vamp, then explicitly says it goes like this, the 4th the 5th ...), and goes vi/IV in the chorus.
answer_details: author: music.stackexchange.com/users/35439/moonwave99
score: 1
sents: text: Depends if you choose to relate it to the key of C major or A minor.
text: If you choose A minor - and if A is established as the tonic you probably should - there's then the additional question of whether to call C III or &flat;III.
text: I know which I prefer - after all, if you call C III, what would you call C&sharp;?
text: (It COULD happen!)
text: But some people disagree, and it's pointless to brush aside an established practice as merely 'wrong'.
answer_details: author: music.stackexchange.com/users/17003/Laurence Payne
score: 1
sents: text: Am F C G - in key Am will make Am i .
text: F is VI , C is III , G is VII .
text: In key C it will make Am vi , F is IV , C is
text: I , G is V .
text: Usually the telling chord in Am is V - E.
text: So if the piece has some E chords, it's more likely to be in key Am.
text: If not, it'll more likely be key C.
text: The last chord is also a good clue to the key.
text: That's what will be the decider as to how you designate the Roman numerals.
text: It's maybe not a good idea to call it a minor chord progression -
text: there's ony one in there!
text: Chord progression in a minor key make it clear that it's not in key C!
answer_details: author: music.stackexchange.com/users/2808/Tim
score: 1
sents: text: -> The axis of awesome 4 chords songs
text: Your example starts with Am: so this one i VI III VII and it is modal.
text: Compare it with: https://en.wikipedia.org/wiki/I%E2%80%93V%E2%80%93vi%E2%80%93IV_progression
answer_details: author: music.stackexchange.com/users/56219/Albrecht Hügli
score: 1
sents: text: I'm not sure what the context of your situation is, but if you can make those chords more than a triad (such as adding dominant/minor 7ths, etc.), it could be possible to determine the key.
text: For example, if: Am -> Am7 F -> Fmaj7 G -> G7 C -> Cmaj7 , then it would definitely be in C.
text: The pattern of this in any given major key is: I -> maj7 II -> m7 III -> m7 IV -> maj7 V -> 7 VI -> m7 VII -> (half diminished)
text: The dominant is a great indicator because it's easier to recognize (in my opinion) and is the only one of its kind.
text: Albrecht Hügli is partially right in his answer, though.
text: This looks like a form of a standard 4 chord progression.
text: It shows up in some form in a large portion of modern songs.
text: In that wikipedia page: https://en.wikipedia.org/wiki/I%E2%80%93V%E2%80%93vi%E2%80%93IV_progression
text: This chord progression exactly matches the example given for the variation termed the "sensitive female chord progression" with the numeral expression "vi–IV–I–V".
answer_details: author: music.stackexchange.com/users/66276/tlake29
score: 1

Summary of the answers:
Am F C G in key Am in Roman Numerals is i VI III VII and In key C is vi IV I V
In key Am, the telling chord in Am is V - E.