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Nashville Number System: A Complete Guide

Nashville Number System: A Complete Guide

The Nashville Number System (NNS) is a popular music notation that originated in the 1950s in Nashville, Tennessee. It was developed by Neil Matthews, who was a bass player and studio musician at the time. Matthews found that the traditional sheet music notation was cumbersome and time-consuming in the fast-paced recording studio environment. He began using the NNS as a shorthand for communicating chord progressions and changes with other musicians, and the system quickly caught on among Nashville’s session musicians.

The NNS is based on a simple set of principles that use Arabic numbers to represent chords. This system allows a musician to quickly play in many different keys, and is highly adaptable for use in any musical style. Matthews’ creation has since become a staple in Nashville’s music culture and has spread to other regions and genres as well. It’s basically a Nashville shorthand of song charts that is better than lead sheets since you’re not stuck in one key.

In this article, we will explore the basics of the Nashville Number System, including its standard notation and how it works. We will also discuss the advantages of using the NNS in music creation and collaboration. Whether you’re a seasoned session musician or a beginner songwriter, learning the basics of the Nashville Number System can be a great resource in your musical toolkit, especially if you ever plan to visit Music City itself.

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The Basics – Scales

Chromatic Scale

First things first. To begin to understand the Nashville Number System, sometimes also called the Nashville Numbering System, it’s crucial to understand chromatic scales and major scales. We’re going to be in C for all of these examples. The chromatic scale divides an octave into 12 equal notes, each a half step (100 cents) apart. Here are those 12 notes:

C, C♯, D, D♯, E, F, F♯, G, G♯, A, A♯, B, (C)

The 2nd “C” is an octave higher than the first. A chromatic scale starting on C can also be written with flats as:

C, D♭, D, E♭, E, F, G♭, G, A♭, A, B♭, B, (C)

Quick Note on Enharmonics

Notes that are the same pitch, from a physics standpoint, yet have different names (eg. F# & G♭) are called “enharmonics.” Musical context is the determining factor on how you should label an enharmonic, meaning it depends on the musical situation you’re in whether to call a note # or ♭ when given the option of both. Other than remembering that the sharp symbol (♯) raises a note by a half step and the flat symbol (♭) lowers a note by a half step, it’s not a major issue. It’s important to keep in mind that the NNS’s primary function is to allow musicians to quickly read music, so don’t get caught up in the weeds of music theory. Just make a decision.

The Major Scale

The Ionian (major) scale is made up of seven notes. The C Major scale, starting on the tonic, contains the following notes:


The second “C” in the scale is not a new note, but rather the same note that we started on, only an octave higher. The DNA of any scale essentially comes from a set pattern of whole steps (eg. C to D) and half steps (eg. E to F). Starting from our tonic, the pattern of wholes and halves for the major scale is: WWHWWWH. This is easiest to see on a piano, as many get confused on why E – F and B – C are both half steps rather than whole steps. The answer: there’s simple no note in-between. Some of this may be obvious to you. And, if so, that’s great!

Now, we can assign each diatonic scale tone a number, which gives us flexibility to talk scale tones in a broader sense, freeing us from a specific key.

Notes of the C Major Scale and their Respective Scale Tone Numbers

This assignment of numbers to scale tones is the foundation of the Nashville Number System.

The Basics – Chords

Diatonic Chords

Basic major chords and minor chords are made up of three notes, each note separated by its neighbor by a major third (M3) or a minor third (m3). Looking at the table above that shows each scale tone’s assigned number, you can start on any note, skip one, and then skip another one, and you have a diatonic chord in the C Major scale. If you start on C, F, or G, you’ll create a Major triad. All others produce either minor triads or a diminished chord. Below we’ve listed all the diatonic, AKA natural chords, in the key of C:

  • C (C–E–G)
  • D minor (D–F–A)
  • E minor (E–G–B)
  • F (F–A–C)
  • G (G–B–D)
  • A minor (A–C–E)
  • B diminished (B–D–F)

Unlike typical chord symbols, the NNS tends to use dashes (-) to indicate a minor chord quality, while major chords have no indicator. Diminished chords (chords built on two minor 3rds) use a degree symbol ( ° ). See below:

  • 1 = C
  • 2– = D minor
  • 3– = E minor
  • 4 = F
  • 5 = G
  • 6– = A minor
  • 7° = B diminished

The chords described above are the natural, diatonic chords in the key of C. Only the notes that are in the C scale are used to create these chords. But that’s not necessarily the way actual songs are written; there’s no rule that says you can’t use, say, a D major or a B♭ chord in a song that’s in the key of C — and, even if there was such a rule, songwriters would delight in breaking it.

Seventh (7) Chords

There are four different types of 7th chords: Dominant 7th chord, Major 7th chord, minor 7th chord, and minor Major 7th chords. In the Nashville Number System, these are notated in a very simple way. A dominant 7th will simply be a chord number, 1 through 7, with a 7 subscript. Major 7th chords can be notated two different ways: first, with a subscript of “Maj7,” or with a triangle subscript. It’s a matter of personal choice which one you use. Minor 7th chords are notated similarly to dominant 7th chords, only there is a dash “-” to the right of the chord number. Finally, a minor Major 7th is notated with both a dash “-” to the right of the chord number as well as either a triangle or Maj7 subscript. See below:

Altered Chords

Altered chords are any chords that have been changed, or altered, from their diatonic form. For instance, if you gave your 5 chord, G Major, a sharp fifth note. So now, it’s no longer G Major, but G Augmented (G B D#), which is notated with a “+”. You can change a lot about a chord to alter it, especially chord extensions, such as the fifth, ninth, eleventh, and the thirteenth. Generally, with the NNS you won’t go past altering the fifth of a chord, and even that’s uncommon.

Inverted Chords or Slash Chords

Chord inversions are a crucial part of understanding the Nashville Number System. It’s extremely common for the bass to play a different note than the root note of the chord. For that situation, we have slash chords. Simply put, the chord goes on top, and the bass note goes on bottom in the form of a fraction. Let’s put ourselves in the key of F major. Our progression is F, F7/A, Bb, B, F/C, C7, F. Here’s what that would look like:

Minor Keys

Let’s talk about one of the more confusing topics surrounding the Nashville Number System: minor keys. Basically, you should almost always write a NNS as if the song is in a major key. For example, if the song is in A minor, write your numbers from the C Major point of view. The reason we do this is to eliminate confusion and tons of dashes for minor indication. You see, in the NNS, even if a song is in minor, you would still write “1-” for the tonic minor chord. Furthermore, the natural 3 chord of A minor is C major, but you’d have to write C major as ♭3 in this case, since we always write charts in the perspective of a major key. So, it’s best practice to write a minor key song in its relative major key.

For example, in the key of A minor, the relative major (the scale with the same key signature) is C. So, writing a chart for a song in A minor, you would use these numbers for your diatonic chords:

  • 6– = A minor
  • 7° = B diminished
  • 1 = C
  • 2– = D minor
  • 3– = E minor
  • 4 = F
  • 5 = G

Notice how it’s the exact same chords and numbers as C major, only starting on A minor.

Take the song “Simple Man” by Lynyrd Skynyrd for example. This song is in A minor, but would definitely be easier to read if you charted it in C major. Here is the recommended way to chart this song:

Simple Man,” Charted in C Major

But, there’s no law saying you couldn’t take the minor approach — most musicians would agree, though, that this is more difficult to read. Here’s what “Simple Man” would look like charted in A minor, the non-recommended way:

Simple Man,” Charted in A minor

It’s pretty clear which one looks cleaner and less cluttered. And, typically, that’s gonna be how you determine which approach to take.

Non-Diatonic Chords

Non-Diatonic Chords, or chords that don’t occur naturally within the scale that you’re in, are notated with sharp and flat modifiers. Let’s give an example. A lot of songs use a particular cadence called the “Mario” cadence. (play it and you’ll see why) In the key of C, this cadence would be A♭, B♭, and finally, C. Now, A♭ and B♭ do not naturally occur in C Major. So, to notate them, they would be called ♭6 and ♭7, respectively. See below the “Mario” cadence:

Mario” Cadence

Let’s look at an example of a song that you would probably actually play in Nashville: Garth Brooks’ “Friends in Low Places.” This song is a good example to better understand non-diatonic chords, because the second chord of the song “just don’t belong” in the key of A Major, seriously. The second chord is an A# fully diminished 7th, and its function is to bring you chromatically from the A Major chord to the B minor chord. Some people may call this chord a B♭ fully diminished 7th, but some people are wrong. My general rule is: If you’re walking upward, as in from A Major to B minor, you sharpen the first chord. Going from A# to B makes sense, but going from B♭ to B does not. Here’s how we would chart “Friends in Low Places”:

Garth Brooks’ “Friends in Low Places

The Basics – Timing & Format

Bars & Beats

Understanding bars and beats in the NNS is crucial, and here’s how it works. Every measure of a song charted in the NNS way gets at least one number. Essentially, new number = new measure. See below Radiohead’s “Creep” charted out, which is actually a pretty common progression, where each individual chord gets 2 measures:

Radiohead’s “Creep”


It’s important to remember the end goal when making a NNS chart: readability. So, formatting a chart in a clean way is essential to make it super readable for musicians on the very first go. That being said, there’s a few general rules to try and follow when making your chart. Generally, music naturally falls into 8 or 16 bar phrases, which can look really nice and symmetrical. It’s recommended to have a maximum of 8 measures per line, with some space between each set of 4 measures. Or, sometimes instead of empty space, some chart makers may use a bullet to separate 4 bar phrases. See below:

When things aren’t so symmetrical, like when you have a random 5 bar phrase, it’s up to you to make it obvious that there is an odd phrase. If it comes after a 4 bar phrase, leave space after the first 4 bars, and then put your 5 bar phrase, but NEVER clump 8 or 9 bars together without any space. The eye will catch the imbalance of the 4 and 5 bar phrase, and the musician reading your chart will immediately understand there is abnormal phrasing. See below:

Split Bars

Many songs use one chord per measure without any variation. But, even more songs will often have 2, 3 or even 4 chords in a single measure in some cases. When you’ve got 2 or 4 chords in a single measure, and they get the same amount of beats, you can simply throw a line under those chords to indicate that they live in the same measure. It’s almost like putting them in the same house together. See below:

Uneven Split Bars

In the cases where multiple chords within the same measure take different amounts of beats, we use little hash marks to show the beat division. See Example 1. And for more complicated beat divisions, we use traditional rhythmic notation or combine pushes with our split bars if that pleases the desired rhythm. See Example 2.

Example 1
Example 2

In Example 1, the second measure has a 4 chord on the first three beats, and then a 5 chord on the fourth beat. Then, the fourth measure reverses that. In Example 2, the second measure gives one and a half beats to the 4 chord, and two and a half beats to the 5 chord. In measure four, the same rhythm takes place, but this time notated with hashes and a push.

Song Sections

On the left hand side of a NNS chart, you will see abbreviations for the song sections. This is for organization, ease of communication between musicians, and to help keep a musician in their place while following the song. See below the different types of song sections and their respective abbreviations.

VerseV or Vr
SoloSolo or So

Notation & Symbols


A push is a common occurrence in music of all kinds. A push simply means that a chord should be “pushed” an 1/8th note early or late, depending on which way the symbol is facing: “<” indicates 1/8th note early, and “>” indicates 1/8th note late.

Quick Note on Pushes

Many musicians use the two push symbols interchangeably to indicate a forward push, as in an 1/8th note early. A back push is way less common in music, but can happen. Just be aware that many musicians use exclusively the back push “>” to indicate a forward push. This is one of the most commonly misused symbols in the NNS.


One of the most common symbols that you’ll come across in the Nashville Number System is what’s known as a diamond. And that’s because it’s actually just a diamond. A diamond can either contain the number, or it can be above it. It’s up to the chart creator. A diamond indicates that you should hit the chord and let it ring until the next chord. See below:


Another important symbol to understand is the marcato ” ^ ” symbol. It functions very similarly to a diamond. But rather than hitting the chord and letting in ring out, you hit the chord and quickly mute it. Also, a chord with a marcato is often accented.

Quick Note about Marcatos

The Marcato symbol has a few relatives that other people seem to use as well. These symbols all mean the same thing: hit and choke the chord. It’s up to the chart maker to decide which one of these to use, though I think the standard Marcato symbol that we discussed above should be the standard. Here are the other commonly used Marcato symbols:


While not used as often as diamonds or marcatos, arrows are an important aspect of the NNS. Arrows are used to indicate walkups and walkdowns. For instance, it’s extremely common in country music to add a walkup when going from the 1 chord to the 4 chord. Similarly, you can do a walkdown when going from the 5 chord to the 1 chord. These are not the only times when walkups or walkdowns may occur, but they are definitely the most common. See below:

Quick Note about Arrows

Arrows can also be used in another fashion. The downward arrow can be used to indicate a breakdown or down chorus, where the song hits its lowest point. Then the upward arrow can be used to indicate the last big chorus or refrain of the song.


Fermatas are used to indicate that a chord should be held for longer than the regular amount of time. It’s often used in conjunction with diamonds at the end of a song, where the final chord should be hit, held, and let ring for longer than what’s actually on the chart. See below:

Other Notation

Repeats are used to repeat entire sections of a songs, effectively saving space on the page. Endings (the numbers inside the circles) are often used in conjunction with repeats, where the first time you’ll play the chords by the 1st ending, and then after repeating, you’ll skip the 1st ending and go to the 2nd ending.

Xs or the No Chord symbol (N.C.) can be used interchangeably, and indicate parts of the song where there are no chords being played, but the beat and maybe even the melody keeps going. Regardless, Xs or N.C. mean you should not be playing a chord.

Ritardando or Rit. for short indicated a section of the song that should gradually slow down. Oftentimes, retardandos are used at the very end section in a song to indicate a gradual slow down until the last chord.

The Crescendo and Decrescendo symbols are used to indicate gradual increases and decreases in volume, respectively. Crescendos are oftentimes used at the end of a breakdown, leading into the final chorus, indicating a gradual build-up back into a high energy part of the song. Decrescendos are often used at the end of song, indicating a gradual softening to the last chord.

Example Charts

Now, here are a few examples of fully charted songs. I highly recommend you listen to the entire song and study the chart. This will reinforce your understanding of the Nashville Number System.

To Sum Up

In conclusion, the Nashville Number System is a highly versatile and widely used tool in the music industry, particularly in Nashville and the country music scene. Developed by Neil Matthews in the 1950s, the system has become a staple in Nashville’s music culture and has spread to other genres and regions as well.

The Nashville Number System’s ability to quickly and easily transpose to any key, its simplicity and ease of use, and its flexibility for arrangement and improvisation make it a valuable tool for musicians and songwriters working in a variety of settings. As technology continues to advance and change the music industry, it’s likely that the Nashville Number System will remain an essential part of music creation and collaboration for years to come.

Whether you’re a seasoned session musician or a beginner songwriter, learning the basics of the Nashville Number System can be a valuable asset in your musical toolkit. By mastering this simple and powerful system, you’ll be able to communicate with other musicians more effectively, work more efficiently in the recording studio, and experiment with new ideas and arrangements with ease, for the rest of your musical life.

All the best,

Grant Larcom

Special Thanks To:

Dr. Trevor de Clercq

Thank you to Dr. Trevor de Clercq for offering his expertise on the Nashville Number System. His book, The Nashville Number System Fake Book, was a major help in my research on the NNS.

Chas Williams

Thank you to Chas Williams, owner of nashvillenumbersystem.com, and writer of The Nashville Number System, for offering his advice and input on this article. Also, he has a great app for making NNS charts.

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