Piano Chord Symbols Guide
Read any chord chart with confidence. Each symbol maps to a formula from the Looty Chords theory registry — the same source used by every chord page, the explorer, and the Reverse Chord Finder.
Basic chord symbols
A bare letter (C) means a major triad. Add “m” for minor (Cm). These two symbols unlock most pop and rock charts.
Seventh chord symbols
C7 is a dominant seventh (major triad + minor seventh). Cmaj7 (or CM7, CΔ7) adds a major seventh. Cm7 adds a minor seventh to a minor triad.
Suspended and added chords
sus2 and sus4 replace the third with a 2nd or 4th. add9 keeps the triad and adds the ninth without a seventh — bright, open color.
Sixth chords
C6 and Cm6 add the major sixth above the triad. C6 shares pitch classes with Am7; the bass note and context decide the name.
Extended chords
9, 11, and 13 symbols stack upper tones above a seventh chord. Pianists often omit less essential tones — see the Voicings guide for practical sets.
Altered, diminished, and augmented symbols
Accidentals on chord tones (♭5, ♯5, dim, aug) change color and tension. Always read the quality (major/minor/dominant) first, then the alterations.
Slash chords
Chord/bass notation (C/E, G/B) names the harmony and the lowest note. Inversions and bass lines both appear this way in modern charts.
Alternate notation
Publishers differ: maj7 vs M7 vs Δ7, m7♭5 vs ø7, aug vs +. Learn the meaning behind each shape; Looty Chords pages list common aliases.
Symbol reference table
Examples use C as the root. Click an example to open the matching chord page.
| Symbol | Name | Formula | Example notes |
|---|---|---|---|
| C | Major triad | 1 – 3 – 5 | C – E – G |
| Cm | Minor triad | 1 – b3 – 5 | C – D# – G |
| C7 | Dominant 7th | 1 – 3 – 5 – b7 | C – E – G – A# |
| Cm7 | Minor 7th | 1 – b3 – 5 – b7 | C – D# – G – A# |
| Cmaj7 | Major 7th | 1 – 3 – 5 – 7 | C – E – G – B |
| Cdim | Diminished triad | 1 – b3 – b5 | C – D# – F# |
| Cdim7 | Diminished 7th | 1 – b3 – b5 – bb7 | C – D# – F# – A |
| Caug | Augmented triad | 1 – 3 – #5 | C – E – G# |
| Caug7 | Augmented 7th | 1 – 3 – #5 – b7 | C – E – G# – A# |
| Csus2 | Suspended 2 | 1 – 2 – 5 | C – D – G |
| Csus4 | Suspended 4 | 1 – 4 – 5 | C – F – G |
| Cadd9 | Add 9 | 1 – 3 – 5 – 9 | C – E – G – D |
| C6 | Major 6 | 1 – 3 – 5 – 6 | C – E – G – A |
| Cm6 | Minor 6 | 1 – b3 – 5 – 6 | C – D# – G – A |
| C9 | Dominant 9th | 1 – 3 – 5 – b7 – 9 | C – E – G – A# – D |
| Cm9 | Minor 9th | 1 – b3 – 5 – b7 – 9 | C – D# – G – A# – D |
| Cmaj9 | Major 9th | 1 – 3 – 5 – 7 – 9 | C – E – G – B – D |
| C11 | Dominant 11th | 1 – 3 – 5 – b7 – 9 – 11 | C – E – G – A# – D – F |
| C13 | Dominant 13th | 1 – 3 – 5 – b7 – 9 – 11 – 13 | C – E – G – A# – D – F – A |
| Cm7♭5 | Half-diminished / minor 7 flat 5 | 1 – b3 – b5 – b7 | C – D# – F# – A# |
| C7♭5 | Dominant 7 flat 5 | 1 – 3 – b5 – b7 | C – E – F# – A# |
| C7♯5 | Dominant 7 sharp 5 | 1 – 3 – #5 – b7 | C – E – G# – A# |
Frequently asked questions
- What does Cmaj7 mean?
- Cmaj7 is a C major triad with a major seventh: C – E – G – B. The “maj” marks a major seventh, not a dominant seventh (C7 uses B♭).
- What is the difference between C9 and Cadd9?
- Cadd9 is a C major triad plus the ninth (D) without a seventh. C9 includes the dominant seventh (B♭) and the ninth, so it carries stronger tension.
- What does a slash chord like C/E mean?
- The part before the slash is the chord; the part after is the bass note. C/E means a C major chord with E in the bass — typically first inversion.
- Why do some charts write Cm7b5 and others Cø7?
- They name the same half-diminished quality. Looty Chords uses clear accidentals (m7♭5) while still recognizing common aliases on chord pages.