The Nashville Number System

  • 03/29/2016
  • JamPlay, LLC
Picture this: You're sitting in a club watching a band. You know a lot of people at this club... heck... you know most of the guys in the band. Towards the end of their set, the lead singer singles you out and asks you to come jam the last few tunes with them. You leave your comfortable seat behind, pick up one of their backup guitars and plug in. There's no music on stage, only a set list full of a bunch of songs you've never played. The other guitarist leans over to you and says, "Nothing to worry about man, this first song is a simple 1, 2, 4, 5 progression, and then in the bridge, we'll go to a 6, 4, 5 and then transition back to the chorus on the 2... we'll come in at the top on the 5 chord." At this point, you breathe a sigh of relief because you remembered reading this article in its entirety, OR you start hyperventilating and wake up from one of your worst dreams ever.

Here's another scenario: You (the guitarist and low male singer) are working up a few songs with a keys player, a drummer and a bass player. You've been trying for months to talk this amazing female singer in to joining your group and she's finally coming over today to check out what you guys sound like. She shows up and starts trying to sing along and everyone quickly realizes that these songs are keyed way to low for her. Well, its easy for you... just grab the capo right? What about the rest of the band? What if you want to try the songs out in a few different keys to find the one that best matches her voice?

Both of the above stories can have a very happy ending if you and your fellow band mates are well acquainted with the Nashville Number System. While the system originated in Nashville among studio musicians to help them transpose country tunes quickly, it is used all over the world and in almost every genre of music to help musicians more effectively communicate amongst themselves.

Learning the Number System depends first on a fundamental understanding of the Major Scale. Let's take a moment and look at what makes a scale, a MAJOR Scale.

Every scale is made up a unique 'chemistry' of whole steps and half steps - distances between notes in a scale (also called intervals). A whole step is defined on the guitar as a distance of 2 frets (for example from fret 1 to fret 3 would be considered a whole step). A half step is defined as a distance of 1 fret (from fret 1 to fret 2). A major scale is made up of 7 different notes separated by its own make up of whole steps and half steps. Let's look at a C major scale played exclusively on the 5th or A string:

C Major Scale

In this scale we have notes C, D, E, F, G, A, B and then the octave C. Since we are building this scale off of the C note, C is considered the "tonic" of the scale. In this example, it is easy to see the whole/half step makeup and thus we arrive at the makeup of EVERY Major Scale. A major scale always is made up of two whole steps, one half step, followed by three more whole steps and one more half step. If we abbreviate "whole step" with a "W" and "half step" with an "H" we can define a major scale by its intervals like this: WWHWWWH.

To illustrate how we can use this interval makeup of a Major Scale to build other major scales on the guitar, we'll just move the above shape down to the 6th or low E string. Thanks to the symmetrical nature of the guitar, we now find ourselves with a G Major Scale.

G Major Scale

Note that by preserving the interval chemistry of the Major Scale and building the scale off of G we have introduced a sharp (#) note. The G major scale includes an F# rather than an F in order to stay true whole steps and half steps that make up every Major Scale. Let's look at another example by moving this same shape to the 4th or D string, but we'll move the scale down 1 fret and start on the E.

D Major Scale

In the Key of E Major, there are quite a few # notes needed to build the scale. If you start from each unique musical note and build a Major Scale off of that note by using the interval makeup for a Major Scale, you will discover that each scale has its own, different set of sharps (#) or flats (b) that are needed to create Major Scales. This set of sharps or flats is called a key signature. So that you don't have to figure out all of the key signatures yourself, I have included a handy circle chart to help you learn them:

The Circle of Fifths

The colors in this chart serve really no purpose except to help you separate the different keys. In other words, I am not illustrating in this chart that there is any relationship between the key of C and the key of Gb.

In the music theory world, there is an order of sharps and flats that is helpful when looking at various key signatures. In case I just lost you... read on! It'll make sense in a second! The order of sharps is FCGDAEB. A handy acronym for remembering this is Fat Cows Go Dancing At Every Ball. The order of flats is BEADGCF (order of sharps reversed). Take a minute to look over the chart and you'll notice that next to each key name is a certain number of either sharps or flats. The amount of sharps or flats follows the order of sharps or flats. In other words, if a key has 3 sharps, those sharps will always be F, C, and G. If a key has 3 flats, they will always be B, E, and A. So when you're looking at the chart and you see that the key of B has 5 sharps, you can assume that the sharps in that key are F, C, G, D, and A. To take this to the next step, if you were to build a major scale off of a B using the whole step/half step makeup, your scale would be: B, C#, D#, E, F# G#, A# and B.

As you look over the sharp keys and flat keys, you'll notice that the same note can be referred to as either a sharp note or a flat note depending on the key signature. For example, in the key of G, the note played on your 2nd fret - 1st string would be called an "F#". In the key of Gb, that same note would be referred to as a Gb. These interchangeable note names are known as enharmonic equivalents.

Okay... so now that we've looked at the interval makeup of a major scale and learned the key signatures, it's time to dive in to the Nashville Number System.

We will begin by assigning a number to each note in the Major Scale. We'll start with examples in the key of C but this applies to all keys. In the key of C, we've got the notes C, D, E, F, G, A, and B. The numbers are always built starting with the tonic in the scale, so if we were to look at each note with its own number, we'd have C=1, D=2, E=3, F=4, G=5, A=6, and B=7. If we were in the key of E, the letter/number relationship would look like this: E=1, F#=2, G#=3, A=4, B=5, C#=6, D#=7. To generate numbers for any key, simply look at the key signature, write the notes out in ascending order and assign a consecutive number to each note.

Next, chords must be built over each note in the scale. To build a chord over any note, start with your root (in this example, C) and stack every other note within the key signature on top of that root. So if the root is C, we'll skip D, use E, skip F, and use G etc. So our C chord in the key of C includes the notes C, E and G or 1, 3 and 5.

Every basic chord is made up of a 1 (or root), 3 and 5. You can keep stacking every other note and you'll get some really cool sounding chords, but for now, we're going to stop at the 5. If you were to build a D chord in the key of C you'd have D, skip E, use F, skip G and use A -- the D chord would consist of D, F and A in the key of C.

Remember that when you are building chords within a specific key, you must stay within the key signature as you are building the notes. When each note in a scale has a chord built over it, you end up with 7 different chords per key.

Play through the following C major example to see an example of how chords are built over a Major Scale:

C Major Scale

As you're playing through this example, you will notice that each chord is either Major or minor with the exception of the chord based of the "B" or 7th note. This one is called a diminished chord which is a minor chord with the 5th lowered a half step. When building chords over a Major Scale, these Major, minor and diminished chords are generated because you are using only notes in the Major key signature of the "1" note and you are stacking chords over different degrees of the scale.

Refer to the above example again. Going from left to right (in ascending order) the C chord is Major, the D and E chords are minor, the F and G chords are Major, the A chord is minor and the B chord is diminished. If we go back to the assigned numbers we looked at earlier, the above illustration could be interpreted like this:

The 1 chord is Major, the 2 and 3 chords are minor, the 4 and 5 chords are Major, the 6 chord is minor and the 7 chord is diminished.

The major/minor/diminished makeup of every Major Scale is the same as the C Major Scale. In other words, when playing the chords built inside a Major Scale, the 1 chord is always Major, the 6 chord is always minor, the 7 chord is always diminished. This is usually illustrated in the following ways: 1, 2, 3, 4, 5, 6, 7 OR with Roman Numerals (the capital letters representing Major chords and the lower case representing minor chords) I ii iii IV V vi vii°.

Grab your guitar, and lets apply the chord numbering idea to some chord progressions in the key of C. Play the following the chord progression:
| C |F | Am | G |
This is a pretty common sounding chord progression. With a little dressing up you could practically build a whole song off of it. If we were to write this using the number system, it would look like this:
| 1 | 4 | 6 | 5 |
The following chart shows how the Nashville Number System applies to almost every key signature:

Learn the Nashville Number System

It can be kind of daunting to look at all those keys at first, but once you break it down, it's not so bad. The best thing to do before you take this system to a rehearsal or gig is to look at a number of common chord progressions, and move them from key to key. Use the chord library and other tools available on the site to help you with chord positions, and be sure to practice with AND without a capo. Here are some more common chord progressions based off of the Major Scale:
| 1   | 2   | 4    | 5   |
| 6   | 4   | 5    | 1   |
| 1   | 5   | 6    | 4   |
The Number System handles chord inversions (a chord with the lowest note other than the root of the chord) by displaying the number of the chord being played, then a "/" followed by the scale number that is being played as the bass note. For example, an A/C# played in the key of E major would be written as 4/6 because it is a 4 chord in the key of E Major with the "C#" being the 6th degree of the E major scale. A G/B chord in the key of G Major would be written as 1/3 because it is the 1 chord with the 3rd degree of the G Major scale as the bass note.

The Number System also deals with chord extensions (notes added to a standard chord built with notes 1, 3 and 5). If we were to write a numbered scale out with 7 chord extensions off of each degree of the scale, it would look like this: 1M7 2m7 3m7 4M7 5x7 6m7 7°7. The "x" stands for a dominant 7th chord such as D7 or A7 which is a Major chord with a lowered 7th and exists naturally in the Major Scale on the 5 chord. Here are some other examples of common chord extensions using the Number System: Dsus + key of G = 5sus
A2 + key of A = 1sus2
G9 + key of C = 5x9 (this chord is a dom7 chord with the 9th
degree, "A" on the top of the chord)
Em11 + key of G = 6m11 There are many more examples, but the general idea behind chord extensions is "do what makes sense and is clear, and if you have to explain your self, fine!"

In the examples shared so far, there has been no chord that goes outside the traditional Major scale. This is not very real world. The Number System deals with outside chords in the following way.

When playing a diatonic (or a naturally occurring chord within the Major Scale) 3 chord, there is no need to notate that it is a minor chord. Everybody just assumes that it is. Quite frequently though, there may be a Major 3 chord or a minor 5 chord. These would simply be written as 3M and 5m respectively. Another common outside chord is the use of a Major lowered 7 chord. This would be, for example, an F Major chord played in the context of a G Major progression like this:
| G   | C   | Em  | D   |
| F   | G   | F   | G   |
In this context, the F chord would be written as "b7M."

You might also see a dominant 3 chord followed by a 4 chord:
| E   | A   | C#m   | Bsus   |
|G#7   | A   | B7   | EM7   |
This would be written as:
|1   | 4   | 6   | 5sus   |
|3x7   | 4   |5x7   | 1M7   |
The system also addresses some basic rhythm communication. If there are a lot of rhythmic variations or hits within a song, there may be a rhythm chart written out on sheet music with rhythm slashes and chord numbers written over the rhythmic markings. If it is a fairly straight-forward piece, you may see something like this:
Pre Chorus:
1	     4	 6	5
(2  1/3)   4	 5	1
It is assumed that there is 1 measure per chord unless otherwise communicated. When there are two chords inside parentheses, it means that the measure is divided evenly giving 2 beats to each chord. This, of course, assumes that we are in 4/4 time. If the arranger wants a chord to be strummed once at the beginning of the measure and held, there will be a diamond drawn around the chord. This is called "playing diamonds". If a chord is to be strummed once and then silenced, the number is usually followed with a "!" or a dot may be placed over the chord number.

While I stated earlier that this system is used across almost every genre, it is most useful with music that has clear chord transitions and is open to interpretations concerning rhythms and positions. Riff-based Modern Rock, Metal and Electronica among others often have specific lines or repeating motifs that can't be communicated using the Nashville Number System. Even with that in perspective, having a handle on this system will greatly improve your ability to communicate with other musicians across many different styles, and help you in your writing and arranging as well.

Happy playing!