🎷 Jazz Theory

Follow these three steps to understand the language of jazz: how chords move (Circle of 5ths) → the most important form (12-Bar Blues) → the most important progression and groove (2-5-1 & Swing).

Circle of Fifths

Each clockwise step rises a perfect fifth; 12 steps bring you home. It is the map of keys — neighbors share the most notes. Tap an outer major or inner relative minor to hear its chord and its 2-5-1.

👆 Tap a key

Three Ways to Read It

1. Count accidentals: steps clockwise from C = number of sharps (G=1#, D=2#...); counter-clockwise = flats (F=1♭, B♭=2♭...).

2. Find relatives: the inner ring shows relative minors — same notes as the outer major (C major ↔ A minor).

3. Write progressions: jazz loves moving counter-clockwise: E→A→D→G→C... exactly the 2-5-1 logic in Station ⑤.

Mini task: start at C and tap four steps counter-clockwise (C→F→B♭→E♭). Hear that feeling of resolving?
How to apply it? Most jazz standard progressions move counter-clockwise around the circle: every chord wants to resolve to the one on its left. Listen to these three classic progressions—notice the strong downward 5th (=upward 4th) momentum of the roots:

Scale Lab: Pentatonic · Blues · Modes

Pick a scale, then tap a root note on the keyboard — the scale lights up (gold = root, cyan = scale tones) and plays up & down.

Major Pent. Minor Pent. Blues Scale Ionian Dorian Phrygian Lydian Mixolydian Aeolian Minor Natural Minor Harmonic Minor Melodic Minor Locrian
Tap a root note first
Major pentatonic (1 2 3 5 6): drop the “clashy” 4 and 7 from the major scale — five notes that always sound good. The shared language of folk songs worldwide, including Bāng Chhun-hong.

12-Bar Blues: The World's Most Important Grid

Blues uses just three chords — I7, IV7, V7 — in a fixed 12-bar loop. Tap a key to transpose the whole form; the blues scale follows.

Standard 12-Bar Form (Key of C)

Blues Scale in This Key

C E♭ F F# G B♭

Formula: 1 ♭3 4 ♭5 5 ♭7 — that ♭5 is the “blue note”, the soul of the blues.

Ready

Write Your First Blues Line

Below is a 4-bar blank sheet. Tap a cell, then pick a note — or hit 🎲 Random. Press play and your line loops over the 12-bar backing!

Scale notes (fills selected cell):
Keep your work:

2-5-1: Jazz's Universal Sentence

Nearly every jazz standard is built from it: iim7 = “tense”, V7 = “tenser”, Imaj7 = “home”. Tap a key; cards are tappable and drag up/down to change inversion.

🎯 Guide Tones: 3rd and 7th

The "personality" of a chord is determined by its 3rd and 7th. Step on them during improv and you'll be steady. They also have a shortest path between them: the 7th slides down a half step to become the next chord's 3rd. The lit keys during playback are the active 3rds and 7ths.

Swing: Same Notes, Different Time

Swing changes timing, not notes: even eighth pairs become long–short (~2:1, like triplet beats 1+3). Compare the same rhythm both ways:

Beat grid (each beat in 3 cells; lit = hit):
Straight: 1 + 2 + 3 + 4 +
Swing: 1 (uh) da 2 (uh) da ...
Next: sing your Station ④ blues line with swing timing — congrats, you're improvising.

🎒 Music Backpacker: Dice Improv

The most beloved moment from the “Traveling with an Instrument” lectures: no instrument needed — roll dice to write a blues line. The secret: the blues scale has exactly six notes, so any roll is a right note. Lesson one of improv: inside the right scale there are no wrong notes.

Step 1 · Roll the Dice

🎵 Pitch die picks the note (1–6 = the six blues-scale tones); 🥁 rhythm die decides the beat: 1–3 quarter note, 4 two eighths (roll pitch twice), 5 rest, 6 hold previous.

Pitch die
Rhythm die

Key:

Blues scale in this key:

Step 2 · Your Two Bars (dice-written!)

Eight beats = two bars. When full, press play — your line loops six times over the 12-bar blues (2×6=12). Repetition itself creates music.

Roll beat 1!

Lecture play: invite an audience member to roll real dice; the host taps results into the screen — the whole room witnesses a blues line being born, then the musicians bring it to life.

🌊 Immersive Venue: Ambience

Play some ambient sounds as a background for practicing, writing, or warming up a lecture. Fully synthesized via Web Audio, no audio files used.

Current: None
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