How to read chord symbols: C, Am, G7, Cmaj7…

The first part of a chord symbol is always its root, the note the chord is built on. In English it is a letter from A to G. French-speaking countries, and several others, use the syllables Do, Ré, Mi instead, so the same chord can appear under two names:

A letter on its own means a major chord: C is C major, D is D major. If the root is a black key, its sharp or flat is part of the name: B♭ (“B flat”) is a major chord built on B♭. Any sharp inside the chord, like the F♯ of D, is not written in the symbol.

A small m right after the root makes the chord minor: its third, the middle note, comes down a semitone. Am is A minor, Dm is D minor, Em is E minor. In French they become Lam, Rém and Mim, with the m stuck to the syllable.

Some books write min or a dash (A–) instead. Watch the case: a lower-case m means minor, while a capital M, when you see one, means major. The guide on major and minor chords explains what that one semitone changes.

A number adds a note. The most common one is 7: a seventh stacked above the chord. There are two sizes, and the symbol tells them apart.

• 7 alone adds the note 10 semitones above the root, a tone below the octave. G7 is G B D F.
• maj7 adds the note 11 semitones above the root, just a semitone below the octave. Cmaj7 is C E G B. French writes it 7M: Do7M. You may also see M7 or Δ.
• m7 combines both pieces in order: a minor chord (m) with a 7. Am7 is A C E G.

The usual trap: a 7 on its own is never the major seventh. Read the letters before the number.

Three more symbols turn up regularly. You don’t need them on day one, but they are easy to decode once the root and the m are clear.

• sus4 (“suspended fourth”) replaces the third with the fourth. Dsus4 is D G A. It often moves back to the plain chord, D F♯ A.
• dim (or °) means diminished: a minor third and a fifth lowered to 6 semitones. Bdim is B D F; French writes Si°.
• A slash names the bass: C/E is a C chord with E as its lowest note. In French, Do/Mi. The guide on chord inversions shows why pianists use them.

Here is every symbol in this guide, all on C. Read each one from left to right: root, then m if any, then the number, then whatever comes after the slash. The chord dictionary does the same for any root.