Guide · Music theory

The Nashville Number System, explained simply

Q: What does 1 4 5 mean in music?

The chords built on the first, fourth and fifth notes of the key. In C that is C, F and G; in G it is G, C and D.

Q: How do you write a minor chord in the Nashville Number System?

With a minus sign or a small m after the number: 6- or 6m.

Q: Is the Nashville Number System the same as Roman numerals?

Same idea, different look. Roman numeral analysis writes I, IV, V and uses lower case for minor (vi). Nashville uses plain numbers and a minus sign, and adds rhythm marks for playing.

Q: Do I need to read music to use it?

No. You need to know the chords in the key, and the chart above covers the common keys.

Q: How do you write a split bar?

Put the chords together and underline them, or put them in brackets: (1 4) means half a bar of each.

The Nashville Number System writes chords as numbers instead of letter names. Each number is a step of the major scale of the song's key: in C, 1 is C, 4 is F and 5 is G. Because the numbers stay the same in every key, one chart works whatever key the singer needs.

Updated 20 Oct 2026

How it works

Take the major scale of the key. Number its notes 1 to 7. The chord built on each note gets that number. In a major key, 1, 4 and 5 are major chords, 2, 3 and 6 are minor, and 7 is diminished. A minor chord is written with a minus sign or a small m (6- or 6m).

Number	1	2	3	4	5	6	7
Chord in a major key	major	minor	minor	major	major	minor	diminished
Key of C	C	Dm	Em	F	G	Am	Bdim
Key of G	G	Am	Bm	C	D	Em	F#dim
Key of D	D	Em	F#m	G	A	Bm	C#dim
Key of A	A	Bm	C#m	D	E	F#m	G#dim
Key of E	E	F#m	G#m	A	B	C#m	D#dim
Key of F	F	Gm	Am	Bb	C	Dm	Edim
Key of Bb	Bb	Cm	Dm	Eb	F	Gm	Adim

Reading a chart

Each number is one bar, unless it is marked otherwise. So the chart below is four bars of 1, 5, 6 minor, 4, played twice. In G that is G, D, Em, C. In D it is D, A, Bm, G. The chart does not change.

Key: G   4/4

Verse:   1   5   6-   4
         1   5   6-   4

Chorus:  4   1   5    6-
         4   1   5    5

The symbols you will see

Symbol	Meaning
6- or 6m	Minor chord on 6
7° or 7dim	Diminished chord on 7 (in C, Bdim)
5⁷	Five seven (in G, D7)
4^maj7 or 4^△7	Major seven on 4
1/3	The 1 chord with the 3rd in the bass (in C, C/E)
b7	A chord built a half step below 7 (in C, Bb)
Underlined, or in brackets: (1 4)	Split bar: both chords share one bar
Diamond around a number	Hit the chord once and let it ring
^ or < above (or before) a number	Push: play the chord a little early, ahead of the beat

Different bands use slightly different marks, especially for split bars and pushes. If something is unclear, ask before the count-in.

How do you write minor keys in the Nashville Number System?

There are two ways to do it, and both are used. Some players number from the minor chord, so the tonic is 1- (in A minor, Am is 1-). Others number from the relative major, so the same Am is 6-. Agree with your band which one the chart uses.

Why session players use it

Change key in seconds. If the singer wants it a tone lower, nothing on the chart changes.
Fast to write. A whole song fits on a scrap of paper, written while listening to the demo once.
You hear the shape. 1, 4, 5 means the same feeling in every key, so you learn songs by their pattern.

Where it came from

It grew up in Nashville recording studios in the late 1950s. Neal Matthews Jr. of the Jordanaires is usually credited with starting it, and Nashville session players spread it from there. Today it is used in studios, churches and touring bands everywhere.

Keep the chart with the song

A number chart is only useful if it is with the recording when you need it. In songdrafts you can set the key on the song, so everyone knows what 1 means, and write the chart in the song's notes or lyrics, next to every take of it. When the band needs to hear it, share the song as one link that plays in the browser, no account needed.

Common questions

What does 1 4 5 mean in music?