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How to Transpose Chords With Nashville Numbers
Heshan Fernando
Co-founder & COO
The singer says the key is too high. In a chart written in chord names, that means rewriting every chord on every page. In numbers, it means saying “let’s do it in B flat” and playing.
That difference is why the Nashville Number System exists, and why session players who learned it never go back.
Numbers describe relationships
Instead of naming chords, you number the scale degrees of whatever key you’re in.
In G major: G is 1, Am is 2m, Bm is 3m, C is 4, D is 5, Em is 6m, F#dim is 7°.
So the progression G–Em–C–D becomes 1 6m 4 5.
That sequence is the same in every key. In B♭ it’s B♭–Gm–E♭–F. In D it’s D–Bm–G–A. The numbers don’t change, only the key does — which means a chart written once works forever, for any singer.
The quality follows the major scale automatically: 1, 4 and 5 are major; 2, 3 and 6 are minor; 7 is diminished. Players know that without it being written, so 1 6m 4 5 is often just written 1 6 4 5 in practice, with the minor implied.
| Degree | Quality in major | Example in G |
|---|---|---|
| 1 | Major | G |
| 2 | minor | Am |
| 3 | minor | Bm |
| 4 | Major | C |
| 5 | Major | D |
| 6 | minor | Em |
| 7 | diminished | F#dim |
Chords outside the key
Written with an accidental before the number.
♭7 is the flat seventh — F in the key of G — which appears constantly in rock and blues. ♭3 and ♭6 are the other common borrowings.
A slash indicates an inversion or a bass note: 1/3 means the 1 chord with the 3rd in the bass, which in G is G/B.
That covers most of what a pop or country chart needs. More elaborate harmony has conventions too, and past a certain point people write the chord names.
Rhythm and bars
Chords grouped in bars, usually four to a line. Two chords in one bar are underlined or bracketed together. A diamond over a number means hit it and let it ring; a dot or a slash marks a rest or a stop.
The notation is compact enough that a three-minute song fits on half a page, which matters when a session player is reading a chart they’ve never seen while the tape rolls.
Nashville numbers versus Roman numerals
Same underlying idea, different conventions and different worlds.
Nashville numbers use Arabic numerals with a lowercase m for minor. Used by working musicians in sessions and on stage, optimised for reading quickly and transposing on the spot.
Roman numerals use case to indicate quality — uppercase I, IV, V for major; lowercase ii, iii, vi for minor. Used in music theory and analysis, optimised for describing harmonic function in writing.
If you know one, the other takes about five minutes.
Common mistakes to avoid
- Writing the key at the top and then forgetting to — a numbered chart with no key is unplayable.
- Mixing numbers and chord names in one chart.
- Using Roman numeral case conventions on a Nashville chart, which confuses readers expecting the m.
- Forgetting the accidental on a borrowed chord, so a ♭7 gets played as a 7 diminished.
- Assuming everyone reads it. Check before handing a numbered chart to a player who might not.
How to do it with Nashville Number Converter
The Nashville Number Converter goes both directions.
- Enter the chords and the key they’re written in.
- Convert to numbers, which describe the progression independently of key.
- Pick a target key and read the chords out.
- Write the key at the top of every chart.
Other music tools are in the tools directory.
Frequently asked questions
Why use numbers rather than chord names?
Because a singer changing key means rewriting an entire chart in chord names, and changing nothing in numbers. It’s why session players adopted it — a key change becomes a spoken instruction.
Numbers or Roman numerals?
Nashville charts use Arabic numerals with a lowercase m for minor. Classical analysis uses Roman numerals with case indicating quality. Same idea, different conventions and audiences.
How are borrowed chords written?
With an accidental before the number — ♭7 for a flat seventh, ♭3 for a flat third. That keeps chords from outside the key readable without abandoning the system.
Final thought
Write one song you play often in numbers and try it in three keys. The system explains itself faster than any description of it does.