How chords are actually built — interval by interval, from the root up, starting in E where we've been living. Not shapes to memorise. Recipes to understand. This goes all the way down: by the end you'll see that every chord in existence is one operation repeated, and that the chord and the scale are the same thing viewed from two directions.
A chord is not a shape your fingers make. That's the lie the chord book tells you. A chord is a stack of specific distances measured up from a single note. That note is the root. The distances are intervals. Change the distances, you change the chord. That's the entire system. Everything below is just naming the distances and learning which stacks have names.
Pick a note. That's your root. Now count fret-steps up from it to find the other notes in the chord. Different chords are just different counting patterns from the same starting note. Memorise the counting patterns, not the finger shapes, and you can build any chord anywhere on the neck without a chord book ever again.
We start on E because that's home this session — the open low E and open high E give us a droning root to hear everything against. But once you have the counting patterns, E is just where we happened to start. Move the root, keep the pattern, you've moved the chord.
Before you can stack anything, you need the measuring stick. Here are all twelve semitone steps up from E, each with its interval name and the note it lands on. This is the only thing you actually have to know. Every chord below is just a selection of these rungs.
One fret = one semitone = one rung on this ladder. The interval name tells you the job the note does in a chord: the 3 decides major or minor, the 5 is the stabiliser, the 7 adds sophistication, everything past that is colour. Learn the ladder and you've learned the alphabet. Chords are just words spelled from it.
The smallest complete chord is three notes: root, a third, a fifth. Build it by stacking two "thirds" — a third above the root, then a third above that. Whether the chord is happy or sad is decided by one rung: is that first third major (4 semitones) or minor (3 semitones)?
The 3rd is G♯ — four semitones above E, a major third. That major third is the entire reason this chord sounds bright. The 5th (B) just holds it steady.
Drop that third by one single semitone — G♯ becomes G. Now it's a minor third, three semitones up. Same root, same fifth, one rung lower on the third, and the whole mood flips to melancholy.
Major and minor differ by one fret on one note. Look at the two open voicings: the only difference is the G string — fret 1 (G♯, major) versus fret 0 (G, minor). That one fret is the difference between happy and sad in all of Western music. It really is that small.
Keep the root and third, now move the fifth instead. Flatten it and you get diminished (tense, unstable, wants to move). Sharpen it and you get augmented (dreamlike, also unstable, floats). Two more triads from the same two-brick logic — you're just choosing different rungs.
Minor third and a flattened fifth (A♯). Both upper notes are pulled in tight. Maximum tension — this chord is a coiled spring.
Major third and a raised fifth (C). The stretched-up fifth makes it hang in the air with no gravity — the chord equivalent of the whole-tone scale from the Trip pack.
Major, minor, diminished, augmented. That's all of them. Every three-note chord in music is one of these four, and they're generated by a single operation — stack a third, stack another third — with two dials: is the lower third big or small, is the upper one big or small. Four combinations, four triads. You didn't memorise four shapes. You learned one machine with two switches.
Take any triad. Stack one more third on top. That fourth note is a seventh, and it's what turns a plain triad into something that sounds like it has an opinion. Which seventh you add — flat (♭7) or natural (7) — combined with the triad underneath, gives you the whole family.
The blues chord. Major triad, flat seventh. That D on top is the ♭7 tension — the whole reason a blues jam sounds like a blues jam. This is the E you've been vamping on all session.
Same major triad, but the seventh is natural (D♯) — one semitone higher than the dominant's. Lush, floating, jazzy. The difference between E7 and Emaj7 is one fret on one note. Again.
Minor triad, flat seventh. Smooth, soulful, the most "at rest" of the seventh chords. This is the Em11 family from Session 01, stripped to its core.
Diminished triad with a flat seventh on top. Dark, unresolved, the sound of a film noir doorway. The ♭5 (A♯) is the tension note.
Every seventh chord is just a triad you already know plus one note on top. Learn your four triads cold, then the sevenths are almost free — you're adding a single brick. The name tells you the recipe: "minor seven" = minor triad + flat seven. "Major seven" = major triad + natural seven. The words are the formula.
Two more moves. Suspend — remove the third (the note that decides major/minor) and replace it with the note next door. Add a sixth — leave the triad whole and drop a sixth on top instead of a seventh. Both are tiny edits to the recipe you already have.
Pull the third down to the 2nd (F♯). No third means no major or minor — the chord is open, unresolved, neither happy nor sad. It hangs.
Push the third up to the 4th (A). Tense, wants to resolve back down to the third. This is the Suspended Orbit from Session 09 — the sus4 pulling home to the major.
Whole major triad, plus a sixth (C♯) instead of a seventh. Sweet, vintage, resolved-but-interesting. The C♯ is the same note that makes E Dorian and E Major Pentatonic sing.
Minor triad with a natural sixth on top — the tension between the minor third (G) and the bright major sixth (C♯) is the exact colour of the Dorian mode. A whole scale's personality in one chord.
Keep stacking thirds and you run off the top of the octave. The next third above the seventh is the 9th, then the 11th, then the 13th. These are the same as the 2nd, 4th and 6th — just an octave up, and named that way to signal "this is an extension sitting on top of a seventh chord." Bend these upper notes and you get the spicy altered chords.
E7 with a ninth (F♯) stacked on. Funkier, fuller, the sound of a soul rhythm guitar. Same F♯ that's the 2 in Esus2 — an octave higher, now a colour on a dominant chord.
The dominant chord with a raised eleventh (A♯). That A♯ is the exact "trippy note" from the E Lydian Dominant scale in the Trip pack. The chord and the scale are carrying the same tension.
Dominant seventh, plus a sharpened ninth — which lands on G. But look what else is G: the minor third. The ♯9 and the ♭3 are the same note. This chord contains the major third (G♯) and the minor third (G) at the same time.
All session we've chased the G→G♯ rub — bending the minor third toward the major, living in the crack between happy and sad. It's the defining feature of your recordings; the analysis flagged G♯ and G nearly tied for airtime.
Here's the depth: the Hendrix chord E7♯9 has both notes in it already. The "♯9" is just the minor third relabelled — G, sitting an octave up, called ♯9 so the theory books don't have to admit a major chord contains a minor third. When you play E7♯9 and then blend E minor and major pentatonic over it, you are outlining the chord. The tension you've been reaching for by ear is the literal harmonic content of the chord you're playing over. The scale is the chord, unpacked into time.
That is the whole game. A chord is a scale stacked vertically; a scale is a chord laid out horizontally. The notes that "work" over a chord are the notes that are the chord and its extensions. Once you see this, you stop memorising "what scale goes over what chord" — you just spell the chord all the way up the stack of thirds, and those are your notes. Chord and scale are one object seen from two angles.
Step all the way back. Everything in this document was generated by a single instruction repeated: start on a root, stack a third, stack another third, keep going.
Seven notes, stacked in thirds, and you've used up every letter — R, 3, 5, 7, 9, 11, 13 covers all seven notes of a scale, because the 9 is the 2, the 11 is the 4, the 13 is the 6. Stack thirds from any root and you generate a whole scale. A fully extended thirteenth chord contains an entire seven-note scale. The chord and the scale were never two things. They're the same seven notes — pressed together into a chord, or spread out into a scale.
Want to know what to play over a chord? Spell the chord all the way up. Root, third, fifth, seventh, ninth, eleventh, thirteenth — that's seven notes — that's your scale. You never needed a separate "scale for this chord." The chord was telling you its scale the whole time. You just had to keep stacking.
The "altered" notes — ♭9, ♯9, ♯11, ♭13 — are what you get when you bend those upper thirds as you stack them. That's the entire content of the A Altered scale from the Trip pack: a stack of thirds from A with every available upper note sharpened or flattened. Maximum tension because every extension is bent. The scale you found "most alien" is just the most-bent version of this one operation.
Here's the payoff for doing it by interval instead of by shape: none of this was about E. E was the starting note. The recipes are counting patterns, and counting patterns move.
Want an A major chord? Root on A, count up 4 semitones for the major third (C♯), 7 for the fifth (E). Want A7 — the other chord in your vamp? Root A, major third C♯, fifth E, flat seventh G. You just built the A7 you've been playing over, from the same recipe as E7, by moving the root and keeping the pattern.
Move the root from E to A. Apply the exact same dominant-seventh recipe. Out comes A7. This is why the E→A7 vamp works and why the same pentatonic sits over both — they're the same recipe on two different roots, seven semitones apart.
Twelve intervals from a root. Stack thirds. Bend the upper ones for colour. Move the root to change key. That is the complete generative system for every chord and every scale in Western harmony — a handful of rules, not a book of shapes. You now own the machine. The chord book was only ever a printout of what the machine makes.