Chord Decoder
Chord names look like a secret language until you know the rules. Type any chord below and it comes apart into its five components — root, third type, seventh type, altered notes, and bass — with the intervals and notes spelled out.
Sharps and flats can be typed either way — Bb or B♭, F# or F♯.
Cmaj7
Major 7
The parts of the name
- CThe chord is built from C.
- maj7Adds a major seventh.
What’s in it
| Interval | Semitones | Note | Name |
|---|---|---|---|
| R | 0 | C | Root |
| 3 | 4 | E | Major third |
| 5 | 7 | G | Perfect fifth |
| 7 | 11 | B | Major seventh |
Notes: C – E – G – B · Interval signature {0, 4, 7, 11}
Learn to do this without the tool
Everything above follows one lesson, step for step. There’s no guesswork in it — chord names are built from a small set of rules, and once you know them you can read any chord in your head.
Chord name decoder ring
Silver and upThe five parts of a chord name and the rule behind each one, with the reference grid for every common chord type. Learn these and you can decode any chord in your head — no tool, no chord book.
Related lessons
Intervals: guitar’s secret decoder ring
Free to watchStart here if the interval names above are unfamiliar. Everything else is built on them.
Reverse engineering voicings: name that chord!
Silver and upThe same skill backwards — take a shape under your fingers and work out what to call it.
Creating chord voicings with barre and shell chords
Free accountKnowing a chord’s notes is half of it. This turns them into shapes you can actually play.
Learn the fretboard properly
Fret Science teaches the guitar neck as something you understand rather than something you memorise — so you can find what you need anywhere on it. Membership unlocks the full courses and their handouts, including the lesson above, plus the rest of the tools.
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