Every previous pack gave you a piece of the map. This one gives you the machine underneath the map. Music theory is not a list of rules someone made up. It is a set of consequences that fall out of one physical fact about a vibrating string — and once you can see the chain of consequences, every rule you were ever told becomes obvious, and the ones worth breaking become obvious too. Eight laws, each one caused by the one before it, each one played on your guitar in E.
Theory is one long because. Each law here exists because of the law before it. If you can play the chain, you own the whole subject.
The harmonic series. A single low E already contains the E major chord and the ♭7. You didn't invent E7; the string did.
The strongest relationship in the series is 3:2 — the fifth. So V pulls to I harder than anything. That pull is the engine.
Stack fifths, fold them into an octave, you get the major scale. It isn't a design — it's what fifths look like flattened out.
Same seven notes, different home. Brightness is just position on the circle of fifths. One note changes per click.
Stack a scale in thirds and the whole scale is one chord. That's why "avoid notes" exist — they're the fold that clashes.
Split the octave evenly (tritone, dim7, augmented) and gravity disappears. That's why these sounds float — and why Henderson lives there.
V7 contains a tritone that wants to collapse by semitones into I. Any chord carrying that tritone can be the V. Hence tritone substitution.
Equal temperament rounds the string's true notes. The blue third and the bent ♭7 live in the rounding error. That's why bending is not "wrong".
Hit your open low E and let it ring. You are hearing one note. You are actually hearing a whole stack of notes — the harmonic series — and the loudest members of that stack are an E major chord plus a flat 7. The guitar can show you this directly: every natural harmonic is one partial of the series, pulled out on its own.
harmonics on the low E string — touch, don't press E h|--⟨12⟩--⟨7⟩--⟨5⟩--⟨4⟩--⟨~3.2⟩--⟨~2.7⟩--| E B E G♯ B D(flat) R 5 R 3 5 ♭7 ← the string plays E7 by itself
What this means for everything else: the major triad isn't a convention — it's the first three different notes a string produces on its own. The dominant 7th chord is the first four. When you play an E7 you're not "adding tension"; you're playing what the low E string already is. That's why E7 is the home chord of the blues and why it sounds finished on its own, which no textbook explains.
TARGET · play the six harmonics slowly · then strum an open E7 (0-2-0-1-0-0) · hear that it's the same objectEvery power chord ever recorded. A root-and-fifth power chord through a cranked amp sounds "bigger" than a triad because the distortion generates the harmonic series of the interval, and the series of a perfect fifth manufactures the major third for you. The amp is playing the note you left out. That's Law 01 doing your job.
The first new note the string gives you is the fifth (partial 3, ratio 3:2). It's the simplest relationship two different pitches can have. So the ear treats a fifth above home as the strongest place to fall from. That is the V→I cadence. It's not a rule; it's the ear following the string.
B7 guide tones → E B|------4------------|------5------| D♯ → E (up a semitone) G|------2------------|------1------| A → G♯ (down a semitone) D♯ A E G♯ full chords e|--2--|--0--| B|--4--|--0--| G|--2--|--1--| D|--4--|--2--| A|--2--|--2--| E|-----|--0--| B7 E
The thing to notice: D♯ and A are a tritone apart. A tritone is the most unstable interval there is (Law 06 explains why). B7 carries it; E doesn't. So B7→E is "unstable thing collapses into stable thing by the smallest possible movement." Every cadence in every style is a version of this. Hold that thought for Law 07 — it's the whole reason tritone substitution works.
TARGET · play just the two-note version twenty times · then the chords · you should hear the two notes inside the chordsHendrix, "Hey Joe". The entire progression — C → G → D → A → E — is nothing but fifths. Every chord is the V of the next one. It walks up the circle of fifths until it lands home on E, which is why it feels inevitable rather than composed. Play it on the top three strings and watch each chord pull the next one in:
e|--3--|--3--|--5--|--5--|--4--| B|--5--|--3--|--7--|--5--|--5--| G|--5--|--4--|--7--|--6--|--4--| C G D A E V of G V of D V of A V of E home
If the fifth is the strongest relationship, the most "related" collection of notes is a chain of fifths. Take seven of them — A E B F♯ C♯ G♯ D♯ — fold them into one octave, and you get E major. The major scale wasn't designed. It's what a stack of fifths looks like when you flatten it.
the stack of fifths — a diagonal e|-------------------------------16----(11)-| B|------------------------14-----------------| G|-------------------11----------------------| D|-----------9-------------------------------| A|------7------------------------------------| E|--5----------------------------------------| A E B F♯ C♯ G♯ D♯ (dropped an octave — it's the same note) the same seven notes folded into one octave = E major A|--7--9--11-------------------| D|-----------7--9--11----------| G|--------------------8--9-----| E F♯ G♯ A B C♯ D♯ E
Why this matters: it tells you which notes are "closest" to home. E's nearest neighbours in the stack are A and B — the IV and V. That's why I–IV–V is the blues, the folk song, the hymn and the punk song: those three chords are the three notes touching each other in the stack. The far end of the stack (D♯) is the note least related to E — which is exactly why the major 7th sounds so fragile and so pretty.
TARGET · play the diagonal, then the scale, alternately, five times · you're learning that they're the same thingHere's the bit that unlocks modes for good. Take the stack of fifths and choose which note is home. Home at the bright end of the stack is Lydian. Home at the dark end is Locrian. Modal brightness is literally position on the circle of fifths. And because the stack is a chain, moving one click darker changes exactly one note by exactly one fret.
| Mode | A string | D string | G string | What changed | Sound |
|---|---|---|---|---|---|
| Lydian | 7 9 11 | 8 9 11 | 8 9 | — (♯4 = A♯) | floating, bright, Landau clean |
| Ionian | 7 9 11 | 7 9 11 | 8 9 | A♯ → A (4) | plain major |
| Mixolydian | 7 9 11 | 7 9 11 | 7 9 | D♯ → D (♭7) | the blues major, E7 country |
| Dorian | 7 9 10 | 7 9 11 | 7 9 | G♯ → G (♭3) | minor with a smile — funk, fusion |
| Aeolian | 7 9 10 | 7 9 10 | 7 9 | C♯ → C (♭6) | natural minor, sad |
| Phrygian | 7 8 10 | 7 9 10 | 7 9 | F♯ → F (♭2) | Spanish, menacing |
| Locrian | 7 8 10 | 7 8 10 | 7 9 | B → A♯ (♭5) | no fifth — nowhere to stand |
Lydian (top) → Mixolydian (3rd click) → Dorian (4th click) A|--7--9--11----------------|--7--9--11----------------|--7--9--10----------------| D|-----------8--9--11-------|-----------7--9--11-------|-----------7--9--11-------| G|--------------------8--9--|--------------------7--9--|--------------------7--9--| E F♯ G♯ A♯ B C♯ D♯ E E F♯ G♯ A B C♯ D E E F♯ G A B C♯ D E
The pay-off: you never need to memorise seven scale shapes again. You need one shape and the order of the dimmer: ♯4, 7, 3, 6, 2, 5. Want E Dorian? Start at Lydian, click three times. Want to know why Dorian sounds brighter than Aeolian? It's one click brighter on the circle — the 6th is still major. This is the entire theory of modes in one finger movement.
TARGET · play the ladder top to bottom over an open E drone · then bottom to top · say the changed note out loud each timeMiles Davis, "So What". Sixteen bars of D Dorian, then the same thing a semitone up, then back. No chord changes to speak of — the entire piece is "home is here in the stack, listen to how it feels." It's the record that proved a mode is a place you can live, not a scale you run. Henderson's whole vocabulary starts here.
Take E Mixolydian — E F♯ G♯ A B C♯ D — and instead of playing it in order, skip every other note: E G♯ B D F♯ A C♯. That's E7, then 9, 11, 13. The whole scale is one chord. Chords and scales are not two subjects; they're the same seven notes stacked two different ways.
e|--2--| F♯ 9 B|--2--| C♯ 13 G|--1--| G♯ 3 D|--0--| D ♭7 A|-----| E|--0--| E R ← E13: the Mixolydian scale as a single chord
Now the useful reverse: if the chord is the scale, then the chord tells you what to play over it. E13 on the chart means "E Mixolydian, and mind the A." Am7♭5 means "Locrian on A" — because that's the only stack of thirds that produces it. You don't look up chord-scale relationships; you unfold the chord.
TARGET · strum E13, then play E Mixolydian over it · then land on A and hold it — hear the fight · then land on G♯ — hear it vanishEverything so far has gravity because fifths are uneven — home is always somewhere. But if you split the octave into equal pieces, every note is the same distance from every other, and gravity switches off. Two equal pieces = the tritone. Four = the diminished 7th. Three = the augmented triad. These sounds float because the maths gives them nowhere to fall.
e|--7--|--10--|--13--| B|--6--|---9--|--12--| G|--7--|--10--|--13--| D|--6--|---9--|--12--| G♯dim7 same same ← it is the same chord at every 3rd fret put E in the bass and the floating chord becomes a dominant with a ♭9: e|--7--| B|--6--| G|--7--| D|--6--| E|--0--| E7♭9 = E + G♯dim7 ← the dominant chord and the diminished chord are the same object
Henderson's displacement trick lives here. Because a dim7 is the same at four places, any dominant-chord lick can be moved up or down three frets and still be "right" — it's the ♭9 sound viewed from a different corner. That's not a rule he learned; it's a symmetry he exploits. The Step Out practice from Pack 04 is this law with a delay pedal.
A|-----1-----| E|--0--------| E A♯ ← the tritone: six frets, no gravity, pure unease
And three-way: E, C and G♯ are each a major third apart — the augmented triad. Coltrane built "Giant Steps" by treating those three as three equal home keys and running V→I into each. That's Law 02 (fifths) applied inside Law 06 (symmetry). Terrifying to play, obvious to see.
TARGET · play the dim7 at 6, 9, 12, 15 · then play E7 → E7♭9 → E · hear the diminished chord as "the dominant, leaning harder"Put Laws 02 and 06 together. The V7 chord works because it contains a tritone (D♯–A in B7) and the tritone collapses by semitones into I (E–G♯). So here's the question: what other chord contains D♯ and A? F7 does — its 3rd is A and its ♭7 is D♯. Same tritone. Same collapse. So F7 can stand in for B7, and it comes with a bass note a semitone above home. That's tritone substitution, and it's not a trick — it's Law 06 saying "the tritone has two roots, pick either."
F7 E the guide tones — identical to B7 → E e|------|--0--| D|--1--|--2--| D♯ → E B|--1---|--0--| G|--2--|--1--| A → G♯ G|--2---|--1--| D|--1---|--2--| A|------|--2--| E|--1---|--0--| bass: F slides down to E — the smoothest arrival there is
Why fusion players love it: the tritone sub gives you a chromatic bass line for free (F→E instead of B→E) and lets you play F Mixolydian or F Lydian dominant over a B7 bar — all those "outside" notes are just the other root's scale. When Henderson sounds like he's a semitone out over a V chord, he usually isn't out. He's on the other door.
TARGET · loop E for four bars · approach it alternately with B7 and F7 · then solo over the F7 bar using F Lydian dominant (F G A B C D E♭) · hear "outside" become "inside"Back to Law 01. The string's own 7th partial — the D — is about 31 cents flat of the D on your fretboard. The string's own 3rd (partial 5) is 14 cents flat of your fretted G♯. Equal temperament rounds every note so that all twelve keys work. The blues is what happens when a player refuses the rounding. The bent third, the flat seventh, the note that's neither major nor minor — those are the string's real notes, reached for by ear.
e|-----| B|--8--| G ♯9 — the minor third G|--7--| D ♭7 D|--6--| G♯ 3 — the major third A|--7--| E E|--0--| E R ← E7♯9: both thirds, on purpose
G|--12b(¼–½)~~~~~~~--| G → toward G♯, not arriving — the blue third
So here's the whole thing in one sentence: theory is the rounded-off version of what a string does; the blues is the unrounded version; and the entire history of guitar is players choosing, note by note, which one to play. Landau bends to the string's note. Henderson exploits the rounding (symmetry only exists because of equal temperament — Law 06 is impossible in just intonation). Hendrix does both in the same chord.
TARGET · strum E7♯9 · then play the blue bend over it · then resolve the bend fully to G♯ · you've just played all eight laws in three secondsA blues in E where every chord is there to demonstrate a law. Nothing in it is a "jazz chord" for the sake of it — each substitution is a consequence you've now played. Loop it, and the theory is in your hands.
bar chord why it's there 1 E7 Law 01 — the string's own chord 2 E7 3 E7 4 E7♯9 Law 08 — both thirds, the blues declares itself 5 A7 Law 03 — IV, E's nearest neighbour in the stack 6 A♯dim7 Law 06 — the floating chord, four roots, no home 7 E7 8 C♯7 Law 02 — V of the F♯m that's coming (a fifth is gravity anywhere) 9 F♯m7 Law 05 — ii, the scale folded in thirds from F♯ 10 F7 Law 07 — tritone sub for B7, same guide tones, chromatic bass 11 E7 home 12 B7 Law 02 — the turnaround, the fifth pulls you back to bar 1 voicings (all verified) E7 E7♯9 A7 A♯dim7 C♯7 F♯m7 F7 B7 e|-----0-------x-------0-------0-------x-------x-------x-------2----| B|-----0-------8-------2-------2-------2-------2-------1-------0----| G|-----1-------7-------0-------0-------4-------2-------2-------2----| D|-----0-------6-------2-------2-------3-------2-------1-------1----| A|-----2-------7-------0-------1-------4-------x-------x-------2----| E|-----0-------0-------x-------x-------x-------2-------1-------x----|
Listen for the joins. Bar 4→5: E7♯9 into A7 — the ♯9 (G) is A7's ♭7, so the fight resolves sideways into the IV. Bar 5→6→7: A7 to A♯dim7 to E7 — the bass walks A, A♯, B (B is in the E7) and the dim7 is A7 with its root raised, floating for one bar before E catches it. Bar 8→9→10→11: C♯7 → F♯m7 → F7 → E7 — a chain of fifths (C♯→F♯) handing over to a tritone sub (F instead of B) so the bass walks F♯ → F → E in semitones. Two engines, one bass line.
TARGET · loop it · play a single motif from Pack 01 through all twelve bars · redesign the motif at bars 6, 8 and 10 the way Pack 01 redesigned it for A7One law per day, in order, over an open E drone. Don't skip ahead — the point is the chain. Day 1 is just harmonics and E7 until you hear that they're the same thing. Day 4 is the dimmer switch until you can call the changed note before you play it. Day 8 is the bend. Then loop The Proof and solo, and for every note you play that sounds "outside", ask which law makes it inside. If you can name it, it wasn't outside.
Laws 01–03 want the cleanest thing you own — Suhr S, Jan Ray off, DCX as the desk, Badger on the edge, so the harmonics ring and the guide tones are audible. Law 04 wants the Custom Standard on the neck SSV — the modes need warmth to separate. Laws 06–07 are Henderson territory: Butter Machine, tone rolled back, Mesa clean with a short TimeLine slap. Law 08 is Landau: Jan Ray on, volume at 7, BigSky plate, and stop the bend where the string tells you to.
Pack 01 taught you to say something. Packs 02–04 gave you the words, the dark and the practices. Pack 05 is why the words mean what they mean. Session 14 (How Chords Are Built) and Session 12 (The Trip) are both special cases of Laws 05 and 03 — go back to them after this and they'll read differently. Everything after this in the series is applied physics.