Music Theory for Guitar
Unlock the fretboard and understand the logic behind the music you play. Learn how chords, scales, and progressions connect across the neck so you can write songs, improvise solos, and play with confidence.
Like Duolingo, but for Music Theory for Guitar. Tomo turns the whole topic into a game you play five minutes a day, until it actually sticks.
24 levels across 4 sections, about 48 minutes end to end, roughly 10 days at five minutes a day. It moves through Finding Your Way on the Fretboard, How Chords Connect in Songs, Melodic Expression and Harmonic Color, and The Deep Structure of Music. It starts from scratch.
Free forever · No credit card · iPhone & Android
Key ideas in Music Theory for Guitar
- Each guitar fret equals exactly one half-step interval
- A whole step consists of two half-steps, which translates to a two-fret jump along a single string
- Most natural notes are separated by a whole step (two frets)
- The only natural note pairs separated by a half-step (one fret) are B to C and E to F
- Standard tuning tunes most adjacent strings 5 half-steps (5 frets) apart
- The interval between the G string and B string is tuned to 4 half-steps instead of 5, shifting the matching unison to the 4th fret
- An octave represents the exact same note letter sounding at a higher or lower register
- From the low E or A string, the standard octave visual shape is two strings down toward the floor and two frets up toward the guitar body
- Sharps raise a note by one fret (one half-step toward the bridge), while flats lower a note by one fret (toward the headstock)
- Raising F by one fret and lowering G by one fret land on the exact same fret, making F♯ and G♭ the same physical pitch (enharmonic equivalents)
- A triad is built by stacking alternate scale steps (intervals of thirds) above a root note
- The standard three-note chord consists of the root, the third, and the fifth
- The third note of the chord dictates whether it sounds major (bright) or minor (somber)
- Lowering the major third by one half step (one fret) creates a minor third, changing the chord's quality
- A standard major chord contains only three unique notes: root, third, and fifth
- Strumming across all six strings merely duplicates those same three notes across higher and lower octaves
You've tried the other tabs
Thirty open tabs. Four facts you actually kept.
You watched. You nodded. By Sunday it was gone.
One answer, then back to scrolling.
Eight weeks. You meant to finish. You didn't.
Tomo gives Music Theory for Guitar the Duolingo treatment: levels, streaks, and quick quizzes that test what you just learned. That game loop is what the tabs above never had, so it's the one you actually finish.
Here's what playing it feels like
A real question from this course. Take your best guess.
To move up a whole step on one string, how many frets do you move?
Get it right to open this lesson and 23 more in the app.
Where Music Theory for Guitar takes you
- 1
Finding Your Way on the Fretboard
- Navigating Notes and Half-Steps
- Building Major and Minor Chords
- 2
How Chords Connect in Songs
- The Major Scale as the Fretboard Map
- The Number System and Song Progressions
- The CAGED System for Neck Mastery
- 3
Melodic Expression and Harmonic Color
- Pentatonic Scales and Lead Phrasing
- Seventh Chords and Colorful Harmony
- 4
The Deep Structure of Music
- Keys, Modes, and Underlying Logic
4 sections · 8 units · 24 levels. Built to play, not to enroll.
Tomo is in ChatGPT
Tomo is also a ChatGPT plugin: the same playable courses, built and played inside your chat.
Add Tomo to ChatGPT- What to ask
- “Make me a Tomo course on black holes.” “Turn this chat into a Tomo course.”
- What you get
- Quick questions with instant feedback, hearts and stars, ready to play in about a minute.
- Where it goes
- No sign-up to start. Connect your Tomo account and your streak carries on in the app.
You pick the voice
Music Theory for Guitar is taught in the Professor style: clear, structured, thorough. Want a different feel? In the app you can spin up the same topic in any of Tomo's teaching styles. Same facts, totally different vibe.
More Music on Tomo
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Guitar Theory: From First Chords to Total Mastery
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How Melody and Harmony Work
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Fretboard Fluency for Guitar
Break out of beginner chord boxes and static strumming. Build fretboard-wide navigation, expressive touch, and harmonically rich rhythm and lead playing.
The Intermediate Guitarist's Toolkit
Move past basic open chords and simple scales to unlock the full fretboard. Learn to connect the neck, refine your tone, and play with professional expression.
Start Music Theory for Guitar today.
Download Tomo, search Music Theory for Guitar, and play your first lesson in under a minute.