# Jazz lite
> Interactive page: [`jazz.html`](jazz.html)
Three notes can carry a seventh chord: the **root**, the **3rd** (major or minor), and the **7th** (major or flat). That is a *shell voicing* — enough harmony to walk a **ii–V–I** without a six-string grip. v2 opens jazz; the dictionary still holds method-book sevenths, not a full extension chart.
Pair with [Play along](songs.md) (progressions, titles only) · [Chord dictionary](dictionary.md) · [Scales](scales.md).
On the HTML page, Play becomes Stop on the same button. Tempo follows the metronome. TAB is A string on top — [Foundations · TAB](foundations.md).
**Sources (two-check):** Berklee ukulele-lab shells (root + guide tones 3 and 7 on compact GCEA grips) · Hal Leonard Jazz Ukulele Method (ii–V–I as the first jazz cadence; swing eighths as a triplet with the first two tied). No copied heads or riffs.
## Shell voicings
Low to high, two useful orders: **R–3–7** (3rd then 7th) and **R–7–3** (7th then 3rd). Same three pitch classes; the 3 and 7 swap which string they sit on. Mute the unused strings.
**String sets:** *A set* = root on the A string (C shells). *G set* = root on the G string (G shells). R–7–3 often skips C so the guide tones stay inside a tight box. Slide the whole grip; the letter follows the root.
## A-string set — C shells
Root C on the A string, fret 3. R–3–7 puts the 3rd on E (or C for the minor) and the 7th on G. R–7–3 skips E and puts 7 and 3 on G and C.
### R–3–7
```
A|-3---3---3------- C
E|-0-------0------- E / · / E
C|-----3----------- · / Eb / ·
G|-4---3---3------- B / Bb / Bb
```
Cmaj7 = C E B · Cm7 = C E♭ B♭ · C7 = C E B♭. Only the 3rd and 7th move. That is the whole colour change.
### R–7–3
```
A|-3---3---3------- C
E|----------------- skip
C|-4---3---4------- E / Eb / E
G|-4---3---3------- B / Bb / Bb
```
Same letters, 7th below the 3rd on the inner strings. Use this when the next chord’s guide tones want to move by a fret or two on G and C.
## G-string set — G shells
Root G on the open G string. Both orders use the same compact grip (root on G; guide tones on E and A). R–3–7 walks 3 then 7; R–7–3 walks 7 then 3.
### R–3–7 / R–7–3
```
A|-2---1---2------- B / Bb / B
E|-2---1---1------- F# / F / F
C|----------------- skip
G|-0---0---0------- G
```
## ii–V–I
The jazz cadence: minor 7 on scale degree 2, dominant 7 on 5, major 7 on 1. In **C** that is Dm7–G7–Cmaj7. In **G**, Am7–D7–Gmaj7. One bar each on ii and V, two bars on I — a four-bar loop.
The room dictionary has open **G7**, **Am7**, and **D7**. It does not have Dm7, Cmaj7, or Gmaj7. Where a seventh shape exists, the HTML loop *strums* it. Where it is missing, you hear a shell (root + 3rd + 7th as fretted notes) — not a fake dictionary entry.
| Key | ii | V | I | How the model sounds |
|-----|----|---|---|----------------------|
| C | Dm7 (shell) | G7 (strum) | Cmaj7 (shell) | A-set shells + dictionary G7 |
| G | Am7 (strum) | D7 (strum) | Gmaj7 (G-set shell) | Am7 + D7 strums; I is the Gmaj7 shell |
Famous-title harmony (no melody): many standards sit on this cadence. Map a loop on [Play along](songs.md) if you want campfire letters in the same keys. Scale work for Mixolydian / Dorian colour: [Scales](scales.md) and [Modes](modes.md).
## Swing feel & muted comping
Straight eighths split the beat in half. **Swing** eighths split it as a triplet: the first two parts tied, then the last part. Count *1-trip-let 2-trip-let*; play on *1* and *let*.
Comping often leaves beat 1 open and *chucks* on 2 and 4 — muted eighths, not a full ring.
```
A|-----------------
E|-x---x---x---x--- muted swing eighths
C|-----------------
G|----------------- 1 2 3 4
```
Hold a C7 or G7 shell in the left hand while the right hand mutes. Compare straight muted eighths on [Exercises · palm mute](exercises.md).
## Dominant 7 → altered colour
A plain dominant is R–3–5–♭7. Jazz players often add *colour tones* a half step above the root: the **flat 9** (♭9) and the **sharp 9** (#9). On G7 that is A♭ and A♯/B♭ — two fretted notes, not a new dictionary chord.
```
A|-2--------------- B (3)
E|-----------------
C|-----------------
G|-0---1---3------- G (root) · Ab (b9) · Bb (#9)
```
The 3rd (B) still says “this is major-third dominant.” The extra notes are paint. Resolve the colour into Cmaj7.
## Three tracks
- **Beginner** — Own Cmaj7 R–3–7. Play the arpeggio walk slow. Listen to G7 from the dictionary.
- **Intermediate** — Add R–7–3 and the G-set shells. Loop ii–V–I in C near 60. Chuck on 2 and 4.
- **Advanced** — Both keys. Swing eighths even. Add b9/#9 on G7, then land on Cmaj7.