Guitar Fretboard Mastery (Fret Science System)

A systematic approach to guitar theory emphasizing geometric patterns and understanding over rote memorization.

Core Concept: The Warp

The most important fretboard concept: the G-B string boundary shifts patterns by one fret.

• Standard tuning uses perfect 4ths (5 semitones) between strings, EXCEPT G-to-B which is a major 3rd (4 semitones)

• Any pattern crossing G↔B shifts one fret toward the bridge (G→B) or toward the nut (B→G)

• This explains why chord shapes change when moved across strings

Pentatonic Scale: Rectangle & Stack

The pentatonic scale is a 5-string repeating pattern with two geometric shapes:

The Rectangle (Red)

• Two notes on adjacent strings spanning 3 frets each

• Contains: 1, 5, b3, b7 (minor) or 6, 3, 1, 5 (major)

• Both right-hand notes can be bent a full step

The Stack (Blue)

• Three adjacent strings with 2-fret intervals

• Contains: b3, b7, 4, 1, 5 (minor) or 1, 5, 2, 6, 3 (major)

• Top-right corner bends full step; lower-right notes bend 1.5 steps

Navigation

• Rectangle and stack alternate vertically in each pentatonic form

• Rectangle and stack alternate horizontally with slight diagonal descent

• Stack connects diagonally to itself one octave higher (Clapton pathway)

Five Forms

All forms derive from shifting the 5-string repeating pattern up strings (accounting for warp): Form 1 → Form 4 → Form 2 → Form 5 → Form 3 → Form 1

Modes: Pentatonic + Fill-in Notes

Six modes are pentatonic scales with two notes added inside the rectangle:

Mode Type Fill Position Brightness

Lydian Major Both right Brightest

Ionian Major Staggered Medium

Mixolydian Major Both left Darker

Dorian Minor Both right Brightest

Aeolian Minor Staggered Medium

Phrygian Minor Both left Darkest

Locrian (b5) doesn't fit this system—it's not built on major/minor pentatonic.

Brightness Order (each differs by one semitone)

Lydian (#4) → Ionian → Mixolydian (b7) → Dorian (b3,b7) → Aeolian (b3,b6,b7) → Phrygian (b2,b3,b6,b7) → Locrian

3nps (Three-Notes-Per-String)

A 7-string universal pattern with only 3 fingering shapes:

• 1-2-4 (half-whole): Scale degrees 7, 3

• 1-3-4 (whole-half): Scale degrees 6, 2

• 1-3-5 (whole-whole): Scale degrees 5, 1, 4

Phone Numbers for String Movement

• Going UP: 7-3-6-2-5-1-4

• Going DOWN: 4-1-5-2-6-3-7

Pattern 4→7 transition shifts one fret (can combine with warp for 2-fret shift).

String Pairs (for horizontal movement)

Memorize the 7 pairs—great for melodic sequences:

• Pair 1: 4/1 → 5/2 → 6/3 (same shape as Pair 5)

• Pairs 2-7 follow sequentially

CAGED System

Five open chord shapes (C-A-G-E-D) become a pegboard for the entire fretboard.

Root Locations

Memorize where roots fall in each CAGED shape—snap any pattern onto these positions.

Layered Hierarchy (for improvisation)

• Root — Home base, most stable

• Triad (1-3-5) — Always consonant, great phrase endings

• Pentatonic — Adds melodic options

• Mode — Full color palette

Triads

Four Types (stacked thirds)

Triad Formula Lower 3rd Upper 3rd

Major 1-3-5 Major (4) Minor (3)

Minor 1-b3-5 Minor (3) Major (4)

Diminished 1-b3-b5 Minor (3) Minor (3)

Augmented 1-3-#5 Major (4) Major (4)

Inversions

• Root position: 1-3-5

• 1st inversion: 3-5-1

• 2nd inversion: 5-1-3

Nine closed-form shapes exist (3 inversions × 3 string groups, warped versions for G-B crossing).

Quick Modifications

From Major: lower 3rd → minor, raise 5th → augmented, lower root 1 fret → maj7, lower root 2 frets → dom7 From Minor: raise 3rd → major, lower 5th → diminished, lower root 2 frets → m7

Intervals

Counting System

• Horizontal: +1 fret toward bridge, -1 toward nut

• Vertical: +5 per string up (toward floor), -5 per string down

• Warp crossing: count diagonally

Reference Table

Semitones Interval Semitones Complement

0 Unison 12 Octave

1 m2 11 M7

2 M2 10 m7

3 m3 9 M6

4 M3 8 m6

5 P4 7 P5

6 #4/b5 6 Tritone

9th = 2nd, 11th = 4th, 13th = 6th (subtract 7)

Harmonization with Thirds

Which Scale Degrees Get Major/Minor Thirds

• Major thirds (4 frets): 1, 4, 5

• Minor thirds (3 frets): 2, 3, 6, 7

Technique

• Play melody on one string

• Add third on adjacent string (major or minor based on scale degree)

• Keep one finger anchored, shift other finger for major/minor

Spread Thirds with Pedal Tone

Capture open string as pedal, play thirds 2+ strings away. Assign scale degree to the note matching the open string to create any modal sound.

Circle of 4ths/5ths

Vertical Movement

Moving up a string = up a 4th (clockwise on circle) Moving down a string = down a 4th (counterclockwise)

The Sequence

4ths: B-E-A-D-G-C-F-Bb-Eb-Ab-Db-Gb 5ths: Reverse order with sharp names

Wraps diagonally around fretboard due to warp.

Fretboard Memorization Exercises

• Combine with pentatonic: Find note everywhere using octave jumps, build pentatonic each time

• Follow progressions: Find roots and build triads for each chord in a song

• Cycle of 4ths on one string: Play B-E-A-D-G-C-F-Bb-Eb-Ab-Db-Gb

• Chromatic one-note-per-string: Move chromatically while changing strings

Octave Shapes (CAGED Backbone)

Two "chess moves" for octave jumps:

• +2 strings, +2 frets (no warp) → +3, +2 with warp

• +2 strings, -3 frets (no warp) → +2, -3 with warp

These shapes connect CAGED positions.

For detailed diagrams, fingering charts, and visual references, consult the references/ folder.