Guitar Theory Knowledge
In-depth guides built for guitarists. No fluff — just the theory you actually need, explained in terms that make sense on the fretboard.
Foundations
The Circle of Fifths
One diagram. Every key. Understand how all 12 keys relate, read key signatures at a glance, and build better chord progressions.
Understanding Intervals
Every chord and scale is built from intervals. Learn all 13 — from minor 2nd to perfect octave — and unlock the ability to construct any sound by ear.
How Chords Are Built
Triads, 7th chords, extensions — decoded. See exactly which intervals stack to create every chord quality and why each one has its emotional character.
Chord Progressions
Roman numerals, harmonic function, and the progressions that power thousands of songs. Learn to build and analyse chord sequences in any key.
Functional Harmony
Why V resolves to I, what makes a ii–V–I so compelling, borrowed chords, secondary dominants — the mechanics of tension and resolution explained.
Scales & Modes
The 7 Modes Explained
Ionian through Locrian — what each mode actually sounds like, how the intervals differ, and when to use each one over a chord progression.
Pentatonic Scales
The backbone of rock, blues, and country guitar. Learn all 5 box patterns, the major/minor relationship, and how to connect positions across the neck.
Guitar-Specific
The CAGED System
Five open chord shapes that repeat all the way up the neck. Master CAGED and you can play any chord or scale in any position, anywhere on the fretboard.
Blues Theory
Dominant 7ths everywhere, the 12-bar form, and the blue note. Understand the theory behind the most influential sound in modern guitar.