Nashville Number System

The Nashville Number System is a method of transcribing music by showing the scale degree on which a chord is built. It was developed by Neal Matthews Jr. in the late 1950s for the Jordanaires to use in the studio and later expanded by Charlie McCoy. This system is similar to older methods like the Roman numeral and figured bass systems that have been used since the 1700s.

This system helps musicians figure out chord progressions quickly. It lets musicians rely on their ears instead of written music, saving time when writing charts. Once a chart is made, it can be used in any key, giving musicians freedom to improvise.

The Nashville Number System is easy to learn, even for someone with basic music theory knowledge. Musicians can use hand signals to show chord changes during a song, making it simple to change keys on the spot. This flexibility is very useful for bandleaders, producers, and singers when recording or performing live. The rhythm section can adjust to the new key using their understanding of harmony.

Scale degrees and major chords

The Nashville Number System (also called NNS) is a way to write music using numbers instead of notes. It works like a music tool called (movable-do) Solfège, which uses words like "Do Re Mi" to show music steps. But NNS uses numbers to show these steps.

In the key of C, the numbers stand for different chords. For example, the numbers 1, 4, 1, 5 mean the band should play a C major chord, then an F major chord, then C major again, and finally a G major chord. The key (like C) can be told at the start, and the numbers stay the same even if the song changes key.

Here’s an example of how numbers can make a part of a song:

Chord type

A number by itself means a major chord. To show a minor chord, you can add a dash or a lowercase m after the number. For example, in the key of D, 1 is D major, and 4− or 4m would be G minor.

If a chord’s starting note isn’t in the scale, you can add ♭ or ♯ symbols. In the key of C major, an E♭ triad is written as ♭3. In the key of A major, an F major triad is written as ♭6.

Other chord types like major sevenths, suspended chords, and dominant sevenths use special symbols: 4^Δ7 5^sus 5⁷ 1 stands for F^Δ7 G^sus G⁷ C in the key of C.

Chords with changed bass notes are written similarly to regular slash chords. In the key of C, C/E (C major with E bass) is written as 1/3; G/B is written as 5/7. The numbers always refer to the scale degrees of the notes in the main key.

Chord inversions and chords with other altered bass notes are notated analogously to regular slash chord notation. In the key of C, C/E (C major first inversion, with E bass) is written as 1/3; G/B is written as 5/7; Am/G (an inversion of Am7) is written as 6m/5; F/G (F major with G bass) is 4/5. Just as with simple chords, the numbers refer to scale degrees; specifically, the scale degree number used for the bass note is that of the note's position in the tonic's scale (as opposed to, for example, that of its position in the scale of the chord being played). In the key of B♭, 1/3 stands for B♭/D, 5/7 stands for F/A, 6m/5 stands for Gm/F, and 4/5 stands for E♭/F.

See also: Chord names and symbols (popular music) § Chord quality

Rhythm and articulation

NNS charts use special symbols to show how music should be played. A diamond shape around a number means the chord should be held for a long time. The marcato symbol ^ or a staccato dot means the chord should be played very briefly. The "push" symbol moves the chord a little earlier in the rhythm. When several chords are written in one measure, underlining the numbers shows which chords to play. In ⁴
₄ time, two underlined numbers mean each chord is played for two beats. For example, 2- 5 1 means a minor 2 chord for two beats, then a 5 chord for two beats, then a 1 chord for four beats. If the measure isn't split evenly, dots or hash marks above the numbers show how long to play each chord. Alternatively, rhythmic notation can be used.

Example

The song "After You've Gone" by Creamer and Layton from 1918 is shown here using the Nashville Number System.

You can listen to how the verse sounds from measures 7 to 23 (Play realization on guitar^ⓘ) and compare it to the regular score (Play^ⓘ).

For the chorus from measures 24 to 43, you can also listen to the version using the Nashville Number System (Play realization on guitar^ⓘ) and compare it to the regular score (Play^ⓘ).