Some songs refer to their key as specifically major or minor, but others use both the major and relative minor as key centers, in an even enough proportion where it can be hard to say whether the I chord or the vi chord is the tonal center.


Cmaj7 | Bm7b5 E7 | Am7 | Fmaj7 E7 | Am7 | Gm7 C7 | Fmaj7 | Em7 | Abmaj7 Bb7 | Cmaj7

This is in the key of C/Am, but it seems like it could be analyzed in Nashville / Roman numerals two different ways:

With C major as the I chord:

I | VIIø V7/VI | VI | IV V7/VI | VI | V V/IV | IV | III | bVI bVII | I

With A minor as the i chord:

III | IIø V7 | I | VI V7 | I | VII V7/VI | VI | V | #VII bII | III

I would most naturally write the analysis the first way, but I can see reasons for doing it the second way (jazz guys like to think in terms of II-V-I relationships, and that could make it necessary to call what I would normally call a VII-III-VI change a II-V-I in minor). What's the more effective way to communicate about this?


A related question: since jazz songs often have changes in tonal center, how should Nashville notation reflect those changes?

  • That Bb7 chord window is Bb11.
    – Tim
    Dec 28, 2013 at 17:36
  • Those chord diagrams are automatically generated by StackExchange– I had nothing to do with it. Although Bb11 would be perfectly appropriate for that progression. Dec 28, 2013 at 20:14
  • @DuncanMalashock I am not quite sure I can follow exactly but nashville notation explicitly takes the keynote and works as if the piece was written in a major mode. So If you have a song in A minor then its 1-A 2-B 3-C# 4-D 5-E 6-F# 7-G#. If your piece in A-Minor would use a C-chord, you'd transcribe it as ♭3. Otherwise NSS could just use the Jazz-style roman numerals for notation...
    – wirrbel
    Dec 8, 2020 at 14:17

3 Answers 3


It seems like the term Nashville Number System (NNS) gets thrown around a lot and different people think of it as different things. From my experience I have seen people use a system, such as yours, involving roman numerals and affixing chord type notation as necessary. From my research just now, it seems that the 'real' NNS uses arabic numerals (standard numbers: 1, 2, 3,...). This seems like the same thing but some of your notation includes function, such as the V/VI. If you translate this to arabic numerals, you have 5/6, which in NNS would be a V chord with the 6th degree of the scale as a bass note. Clearly these are not the same thing, so there is some ambiguity about the term.

This link will take you to the best NNS chart I could find and it happens to be interactive and have a full description of what is happening. You can see that the original keys are circled in the top left, A and E. You can see the modulation marked as a circle around "mod down (arrow) to 5" and "mod up to original key". I've also seen the number of the key you are modulating to circled with an arrow pointing up or down with no "mod". After the key changes you can see that the author also put the key of the original song in a circle on the left side of the chart, which can also be the where you indicate the modulation by number, though putting it on the right may be considered easier to read on the fly by some. An interesting spot from the link is at the end of the chorus, transitioning into the bridge. The riff from the chorus starts in the last bar of the chorus, which is written in the key of the chorus, 5, making the last chord of the chorus b7. I would analyze this differently, placing the modulation before that bar and calling the chords 1 and 4, as in the following section. I assume the author made the choice for readability and placement on the chart within the form and/or to remain within the key through the end of the section. I'm not sure how this author would fit a modulation in the middle of a phrase or section but I have seen others kind of just cram it in, place it above or below, or extend the line on the chart.

Within the notation system that I have been using, and thought was NNS, I would write the key with a colon, such as "Amin:" but this does not comply with the basic concept of NNS, to have no necessary connection to a specific key. I would analyze the example progression as:

Amin: III | II V | I | VI V | I | Fmaj: II | V | I | Cmaj: III | bVI bVII | I |

I like to include chord symbols like 'maj7' and '-7b5' but it is not necessary unless it is something outside the key, like a II-7b5 in a major key, or if you are playing in a genre that doesn't usually include such a chord type. If I were to add roman numerals in place of 'Amin', and so forth, it would start to look pretty messy and not very readable, as the only distinction between chord and key change is the ':'. If someone gave me that chart I would have to bust out a highlighter. To adapt my approach, I would use an arabic numeral, so, assuming we are in C, 6 in place of Amin.

So, how you choose to notate this will likely have to do with who will be reading it. I mostly use roman numerals for analysis and prefer to use specific note names when I write charts, as they will only be played in that key. If you are writing charts for songs that will be played in different keys, you will want to include as much as you think will be useful to the player. Like you said, jazz guys think of things in II-V-I relationships and they would probably like it if the keys were mapped out as they were in my analysis. On the other hand, that many modulations may confuse or overwhelm another player. The fragment in your example can easily be described in one key, which you did but you would need some chord symbols in a few spots, like the Gmin should be labeled V-7. For a player that would prefer less modulations to read, I would suggested only modulating when you are going to the destination key for an extended period of time or if the destination key is so unrelated to the original that chord symbols are necessary on most or all chords.

  • Thanks very much– I can see the ambiguity there between the more classical practice of describing secondary dominants (V7/vi) and the more jazz/pop notation of slash chords with alternate bass notes. I can appreciate that the player's background is possibly going to contribute more to how understandable a chart will be than how it's prepared. Maybe for jazz changes with frequent modulations and tonicizations, it's more helpful to write charts in an explicit key, since keeping both the key and changes abstracted adds even more complexity. Dec 28, 2013 at 16:22

Well, the tonal center can be changed in a song, especially in a jazz song. So this one could start off with a C major and then go in a A minor.

Since it starts with Cmaj7 and ends with Cmaj7, I would say it's in C major. So, like you said, it's

I | viiø V7/vi | vi | IV V7/vi | vi | v V/IV | IV | iii | bVI bVII | I

I would say it doesn't change to A minor. It simple follows the IV - V - I form with some changes/substitutions.

For instance: The VII can work as the V because they have only one different note (VII is B D F A and the V is G B D F).

For the same reason, the VI can work as the I

The III can also work as a V (the III is E G B D while the V is G B D F).

So the first seven bars would be:

 I | V | I | IV V | I | V I(minor 7th) | V |

Now, about the Abmaj7, I'm not entirely sure. But it doesn't change the tonal center, because (usually) when the tonal center is changed, you will find a V - I. So, if the tonal center had changed to, let's say, Ab major, you would see something like | Eb7 | Abmaj7|

So I would say it's just a small passage that sounds good the ear (of the composer, at least) and then ends with I (Cmaj7)

Also, the C7 might be the V of F major. So on the 6th bar, it would be:

| V(of C major) V(of F major*)| I | VII** |

*this is where we change the tonal center

**but if we had changed the tonal center to F major, the VII would be Em7b5 (half diminished) but it's just Em7.

So, like I said before (for the Abmaj7), it's just a small passage from different tonalities

Update: The C major and the C harmonic minor have the same V ( G B D F ), so when you play V on the major one, you can play a chord from the harmonic minor next.

Like in the example, you play III (That also works as V) and then Abmaj7 which is the VI of the C harmonic minor

  • 1
    Thanks for the response. My example is an attempt to show a situation where there's ambiguity; in other words, it could end on Am in measure 5, and it'd be less clear that it was exclusively a major tonality. I'm less concerned with the mechanics of this particular example, and I'm really looking for the best practice on how to adapt an abstract notation like Roman numeral / Nashville to a situation where the key center is ambiguous or changing. Dec 27, 2013 at 21:59
  • Well, usually, the tonal center is being established by playing a V - I relation, so what I do is to look for those kind of chords (when I'm not sure which tonal center I am in). Also, keep in mind that when you are stuck in a bar, you can go to the next one to see what kind of chords are being played and see if they help you determine the tonal center. Dec 27, 2013 at 22:06
  • I finally remembered what the Abmaj7 is. I updated my answer Dec 28, 2013 at 9:49

There seems to be an awful lot of contrasting stuff out there regarding NNS. Purists say it needs to be with Arabic nos. ( 1,2,3 etc). The numbers seem to assume the basic chords will be maj,min,min,maj,maj, min,dim in triads. A - sign can go in front or behind the chord number,to denote min.In handwritten stuff, it's easy to miss that .

The Roman numeral derivitive of NNS is better, in my opinion, as lower case numerals will denote minors.Imagine you want to modulate from ,say, C to G. You'd use a D maj. to get there. But in this system, 2 is going to be minor ? But, in any case, what's wrong with assuming it's all major, unless we're told, with a m after the number ?

To your question - again, it's personal choice. Since "everything starts with major ", it probably makes sense to notate a minor song with vi (or 6) for the first chord. Mostly, songs start on the key chord, so this will alert the reader to the fact it's in a minor key.There again, don't we check the last note/chord to establish a home key ?

Why would we assume that the first chord in your sample song will be maj.7 ? In NNS, the flavour of the chord is denoted, e.g. 57b9, or V7-9. This makes it all more categorical.

I think, rather like we know two flats denote either Bb or Gmin (or, of you like C dorian, etc, but that's another can of worms) - work from the major.

  • I'm with you on the importance of being able to specify the chord quality if you've got changes that aren't diatonic to the key, but I also see the value of using Arabic numerals for easier reading. It seems like there may not be a strict agreement on best practices here. Dec 28, 2013 at 16:16
  • 1
    The original appears to be Arabic numbers. I've used Roman numerals for the last 50 years- if it didn't work, I wouldn't have !
    – Tim
    Dec 28, 2013 at 17:07
  • i personally prefer Roman numerals for chords and Arabic numerals for solfege.
    – mey
    Feb 16, 2015 at 7:37

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