Rundown: Chords to Nashville Numbers by Oblique Endeavors

Rundown rewrites a chord chart in place, turning chord symbols into Nashville
number degrees. Eb Gm Ab Bb becomes 1 3m 4 5.

In a Nashville session, the rundown is the run-through where the band plays a
song once and everyone writes their number chart. This does that part for you.

Open a page with a chord chart, click the toolbar button, and the chart is
renumbered where it sits — lyrics, spacing and column alignment untouched.
Click again to put the original chords back. Nothing is changed permanently,
and nothing is uploaded anywhere.

WHAT IT DOES

• Detects the key automatically, and shows you its ranked runners-up so you
can override it in one click when a song is ambiguous.
• Numbers minor songs from the relative major by default, the way session
charts are usually written, so a minor song reads 6m-centred. Prefer to
number from the minor tonic instead? One toggle, remembered for next time.
• Keeps the chart readable: extensions render as proper superscript, so a
five chord with a seventh does not come out looking like "fifty-seven".
• Handles slash chords, extensions, suspensions and borrowed chords, and
spells degrees properly — an F# in C reads #4, while a Gb in C reads b5.
• Survives the page's own transpose controls; the numbers stay put.
• Copy a renumbered chart and you get readable text, not run-together digits.

PRIVACY

No accounts, no tracking, no analytics, no servers. The extension stores one
setting — how you like minor songs numbered — in your browser. It reads the
page only when you click the button, and never sends any page content
anywhere.