The Nashville number system
The Nashville number system writes chords as numbers: the degree of the key each chord is built on. In C, 1 is C, 4 is F and 5 is G; in G, the same 1, 4 and 5 are G, C and D. A chart written in numbers can be played in any key at sight, which is why session players use it.
The Nashville number system chart
Every major key with its seven chords as numbers. Find the key of the song, and each number in the chart is the chord across from it.
How the numbers are written
- 1 to 7: the chord on each degree of the major scale. A plain number is a major chord.
- 2m or 2-: a minor chord. In a major key, 2, 3 and 6 are usually minor: 1 2m 3m 4 5 6m 7°.
- 57, 4maj7, 2m7: sevenths and other added notes follow the number, as they follow a chord’s letter.
- 1/3: a chord over a bass note: in C, C over E.
- b7, b3, #4: a chord on a lowered or raised degree, borrowed from outside the key: in C, b7 is B♭.
- Each number is usually one bar. Two or more numbers underlined, or in brackets, share a bar.
Why use numbers?
A chart in numbers does not change when the key does. If the singer wants the song a step lower, the band plays the same chart in a new key; the numbers also show how the chords work, the same 1–4–5 in every key. Roman numerals (I–IV–V) say the same thing; the Nashville system uses plain numbers because they are quicker to write and read.
What about minor keys?
Most Nashville charts number a minor-key song from its relative major, so a song in A minor is written in C, starting on 6m. Some players number from the minor tonic instead and write 1m. Either way, agree it before the count-in.
Hear these numbers as progressions on the common chord progressions page, see every key’s chords on chords in every key, or turn on numbers under every chord in the chord chart maker, which prints them on a mandolin chart.