Chord symbols: how to read and play them

A letter alone: major written C

A capital letter on its own is the major chord on that note: C is C, E and G. It names the chord, not the octave or the order of its notes; how to lay them out is yours to choose.

At the keyboard: Put your thumb on the root and play every other white key up from it, root, third and fifth. On D, E and A the middle note is the black key just right of the white one.

m: minor written Cm, Cmin, C-

A small m after the letter makes the chord minor: the middle note a half step lower. Am is A, C and E. Some books print min or a minus sign; all mean the same.

At the keyboard: Find the major chord on the root and lower its middle note by one key. On A, D and E the minor chord is all white keys.

7: the dominant seventh written C7

A 7 alone adds the note a whole step below the root's octave to the major chord: G7 is G, B, D and F. It is the dominant seventh, the chord that pulls a tune home, and the most common symbol after the plain letters.

At the keyboard: Play the major chord, then add the seventh: one whole step down from the root's octave. A three-note shortcut drops the fifth: root, third and seventh.

maj7: the major seventh written Cmaj7, CM7, CΔ

maj7 adds the note just a half step below the root's octave: Cmaj7 is C, E, G and B. The "maj" belongs to the seventh, not the chord. Some books write M7 or a small triangle.

At the keyboard: Play the major chord and add the note one key below the root's octave. A soft, open sound: it doesn't need to go anywhere.

None of the 11 library pieces whose chord symbols name their notes prints it.

m7: the minor seventh written Cm7, Cmin7, C-7

m7 is the minor chord with the note a whole step below the root's octave: Dm7 is D, F, A and C. It is the ii7 of the ii–V–I that jazz and pop lean on.

At the keyboard: Play the minor chord and add the seventh, a whole step down from the root's octave. On D, E and A it is all white keys.

dim and °: diminished written Cdim, C°, C°7, Cø7

dim or a small circle makes both upper notes of the chord a half step lower than major: Bdim is B, D and F. °7 adds a fourth note a minor third higher still (B°7: B, D, F, A♭), and a circle with a slash, ø7, the minor seventh instead (Bø7: B, D, F, A).

At the keyboard: Stack two minor thirds: three keys up, then three more. The chord sits on the seventh step of a major key and leads up to the tonic.

aug and +: augmented written Caug, C+, C(#5)

aug or a plus sign raises the top note of the major chord a half step: Caug is C, E and G♯. It sounds unsettled and stretched, and usually moves on at once, often by the raised note going up.

At the keyboard: Stack two major thirds: four keys up, then four more. Every augmented chord is made of three equal steps, so there are only four different ones.

sus4 and sus2: suspended written Csus4, Csus2, Csus

sus takes the third out and puts the fourth in its place (sus4: C, F, G) or the second (sus2: C, D, G). Without a third the chord is neither major nor minor, and a sus4 usually falls back to the plain chord.

At the keyboard: Play the major chord and move its middle note up one white key for sus4, or down a step for sus2. Then play the plain chord after it and hear the fourth resolve.

None of the 11 library pieces whose chord symbols name their notes prints it.

A slash chord: C/E written C/E, G/B, F/C

A letter after a slash is the bass note: C/E is the C chord over E, so the lowest note is E, not C. It is often an inversion of the chord, and sometimes a bass line moving under a chord that stays still.

At the keyboard: Play the slash's note low in the left hand and the chord before the slash above it, in either hand. C, C/B, Am, Am/G walks the bass down while the chord barely moves.