reading the chips
1 4 5 = major
6- / 6m = minor
5⁷ = add the seventh
badges: H home · A away · T the question · h sad cousin
THE NASHVILLE NUMBER SYSTEM
so 1 · 5 · 6- · 4 =
the numbers never move — tap a key to pin it, or let it roll
SEC·01
Tonicization — you visit
Inside Moves
Borrow one or two notes to spotlight a chord inside your key as a temporary tonic — then hand them back. The ear never stops hearing home. Secondary dominants, borrowed chords, passing diminisheds: rented tension, returned on the next downbeat.
SEC·02
Modulation — you move in
Moving Out
Actually change the address. The tonal center shifts, you cadence in the new key and stay long enough that the ear resets its sense of home. Every technique here is a different moving truck — same cargo, different route.
SEC·03
Color — you redecorate
Staying Home
Same key, same progression — richer paint. Suspensions, added tones, bass lines, pedals, clichés, modal gravity: everything that makes plain triads sound produced, with almost zero accidentals of risk. If “my songs sound simple” is the itch, scratch here first.
NNS legend
1 4 5 major (plain number)
2- 3- 6- minor (dash)
5⁷ dominant 7
1Δ⁷ major 7
°⁷ / ø⁷ dim / half-dim
b7 · #5 chromatic degrees
1⁵ power chord
Theory
ground floor first · machinery secondStart Here — everything you need to play, and nothing you don't
GROUND FLOOR start here — enough to use everything on this site
The Nashville Number System — the beginner's course
THE MACHINERY intermediate → advanced — why the moves work
Dominant Chains — why 7ths pull to 7ths
Key Concepts
33 ideas the moves are made of · highlighted terms across the site land hereModes
one pitch set · seven front doors · bright → darkDefinitions
the technical vocabulary · dotted words across the site land here · ← Back returns youPhilosophy
what sounds good, and why · grounded in psychoacoustics, music cognition, and the physics of this instrumentField Notes
condensed research · sourced, verified, playableStaying Home
30 colors · same key, richer paint · (almost) zero accidentalsInside Moves
40 tonicizations · easy → advanced · home key never changesChains — combining the moves
Moving Out
40 modulations · easy → advanced · pack the truckChains — moves that stack into departures
Progressions
13 genres · the changes that built them · reharm variants marked ↳Scale Choices — what to play over the top
Soloing
what to play over the changes · then recolor one tonicThe Picker — which scale over which progression
One Tonic, Many Colors — swap a note, change the world
Lab
test ideas · build chord by chord — the lab names what you played and suggests where to goYour progression
Inside moves from here
Ways out from here
Rhythms
40 patterns · grouped by genre · dynamics included
Notation
↓ ↑ full stroke
↓ ↑ soft / ghost (play quietly)
✕ chuck — muted percussive hit
· rest (hand keeps moving)
B T i m bass / thumb / fingers
Technique
15 core techniques · how to do it · what it's musically forSongbook
20 complete songs · all public-domain compositions · every chord tappable, every song transposable · plus yoursMy Songs
write your own · exact songbook format — tappable chords, per-song key, saved in this browser
New song
autosaves on this device ·lyric lines: put the caret where the chord lands, tap the pad · riff lines: chips only · the preview is exactly what the Songbook will show
Chord/Scale Atlas
Chord Finder
name a shape · tap frets, toggle O / ✕ above each string — the name appears—
tap some frets
Song Decoder
understand any song · paste a letter chart → key → numbers → the moves it's made ofPaste a chart
letters (C, Am7, F/A, Bb6/9 …) · | for bars · [Verse] or "Chorus:" for sections · anything unreadable is skipped, never fatal
paste the JSON an AI chat returned from the copied prompt — it becomes clean chart text and decodes with the site's own analysis
Test Yourself
name → make the call → answer revealed · K / D / N on keyboardWriter
arrange a song · chords, melody & lyrics in numbers — everything transposesWrite a Song
tap chords in on the pad — the amber section catches every Add · tap a chip to edit it · melody & rhythm as before
My Originals
saved under this username, synced with everything else
Solo Harmonizer
tap your solo notes · get the chords that hold themChromatic numbers — 1 is the key's root, count every fret: in C, 1=C · 2=Db/C♯ · 3=D …
your solo
Saved
your songs, bookmarks & profileProfile & Sync
everything on this tab saves under this username
My Songs
log what you've learned — write the progression in NNS and the chords stay clickable
Lesson Bookmarks
hit the ☆ on any card — it lands here as a jump link