Chord Symbols

Chord symbols are plain-text abbreviations of chords, for example F, Asus4, Em7 and G7−9. These often refer to standard chord boxes that can be found in chord dictionaries or even within the transcription of a song. Thus, a musician can grasp the basic harmony of a song without having to learn how to read musical notation.

This is not a chord dictionary or reference. Instead, my aim is to explain how chord symbols work, how to avoid confusion and how to be consistent. Ideally, with the knowledge presented herein, you should be able to construct your very own chord voicings from chord symbols—and the other way around: putting the proper abbreviation on a chord you just invented!

Chord symbols are nowhere as clear, or even standardized, as staff notation. Furthermore, it seems like the parameters have changed subtly over the years, and/or there have been competing systems. I will try to be as consistent as I can and present the system that most of my sources seem to agree on. But it is unavoidable that I will also need to devote a small section of the article to discussing the alternate notational systems that exist, which can and do cause confusion.

The Basics

Chord symbols are built on uppercase musical letters that indicate the root note, e.g.: C, E, F♯ or A♭. They are assumed to be major chords unless the minor mode is indicated via the suffix m: Cm, Em, F♯m, and so on. If there are no other letters, numbers or characters in the chord symbol, it is therefore a major or minor triad in root position. (Henceforth I will mostly use the root C for consistency.)

The fifth of the chord is assumed to be perfect, barring an alteration sign in the chord symbol. The alteration sign can be either a musical flat (♭) or sharp (♯) sign, or a minus (−) or plus (+) sign. This article will be using the latter, since it is my personal preference. Note: most chord members can be altered, but an orphaned alteration sign is usually assumed to refer to the fifth.

Extensions into four-note or bigger chords are indicated by numbers signifying which interval(s) to add: 6, 7, 9 and so on.

Should the bass note differ from the root note, it is written following a slash (pronounced "over"): C/E, D/A. The bass note need not necessarily be part of the chord: C/F♯, E/C, etc.

Triads

Here are the four common (and two uncommon) triads together with their chord symbols:

• Major triad: C
• Minor triad: Cm
• Diminished triad: Cm−5 or Cm♭5
• Augmented triad: C+5 or C(♯5)
• "Minor augmented" triad (root, minor third, augmented fifth): Cm+5 or Cm♯5
• "Major diminished" triad (root, major third, diminished fifth): C−5 or C(♭5)

As you can see, certain combinations require the use of parentheses in order to make clear that the symbol contains an altered fifth rather than being an enharmonic chord. Note also that the symbols for diminished and augmented chords are explicit about the intervals rather than referring to the common chord names.

Four-note Chords

When adding notes to triads, the standard form is the interval as it appears in the major scale, irrespective of whether it's a minor or a major triad. The exception is the minor seventh.

Add a 6 to the chord symbol to indicate a sixth chord:

• Major sixth chord: C6
• Minor sixth chord: Cm6

Add a 7 to the chord symbol for a minor seventh, and "maj7" for a major seventh:

• Dominant seventh chord: C7
• Major seventh chord: Cmaj7
• Minor seventh chord: Cm7
• Minor major seventh chord: Cmmaj7 (note extra M!)

Last but not least in this category is the very special case:

• Diminished seventh chord: Cdim7

The chord symbol does not specifically state it, but a diminished seventh chord contains a minor third.

Extended Chords

The extended chord symbols obviously signify which note has been added to the basic chord:

• Dominant ninth chord: C9
• Eleventh chord: C11
• Thirteenth chord: C13

However, it is assumed that the larger chords also contain all the intervening notes. A C9 is a C7 with an added ninth. A C11 is a C7 with an added ninth and an added eleventh. A C13—well, I think you get the idea.

In these chord symbols, the "m" and "maj" still refer to the third and seventh. 9ths and 13ths are always major unless specifically altered, and an 11 could never be minor or major as it is a perfect interval.

Thirteenth chords are commonly simplified into sixth chords with one or two of the other extension notes. As such, they can get a more descriptive symbol, for instance C7/6 or C6/9, or the transcriber might just specify a 13 chord on the assumption that the performer will use a suitable voicing that captures the essence of the chord.

Altered Chords

Just as the previously discussed fifth, the extension notes can also be altered. This can occur in just about any combination, but due to enharmonic equivalence, not all permutations result in unique chords.

• Ninth chords normally add a major ninth. The ninth can also appear in its minor form (−9) or augmented (+9). An augmented ninth sounds like a minor third, a diminished ninth like an octave.
• An eleventh chord contains a perfect 11th (4th) in addition to all the other notes. It can sometimes be augmented (+11), but not diminished, as that sounds like a major tenth (third).
• The 13th is generally not altered— the minor 13th being identical to an augmented fifth and an augmented 13th a minor seventh.

In order to make reading easier, altered notes are separated in chord symbols—C7−9 instead of just C−9, C7+9+11 instead of C+9+11, and so on. An altered fifth is generally placed last in the chord symbol (C7+9−5), and an orphaned alteration sign at the end of the symbol is assumed to refer to the fifth: Cm7+.

Other Chords

Sus

Suspended chords are chords where the third has been temporarily replaced by a major second or a perfect fourth. These are written Csus2 and Csus4, respectively. If the seventh is also present, the symbol becomes C7sus2 or C7sus4. As such, these chords are neither minor nor major.

Add

The add symbol is used to indicate that an extension note has been added without "filling out" the intervening space with the notes normally assumed by the 9 and 11 chord symbols.

• Cadd9 is a C major triad with the addition of a (major) ninth, but not the intervening seventh.
• Cadd11 is a C major triad with the addition of a (perfect) 11th, but neither the seventh nor the ninth.
• C7add11 is a C11 shape that lacks the ninth.
• Variants of 13 chords are normally analyzed as sixth chords.

In certain places, you might see add2 instead of add9, and add4 instead of add11. These are to be regarded as interchangeable.

No

You might run into chord symbols that contain "no3" or "no5", often within parentheses. This means that the chord voicings contain no third or no fifth, respectively.

When do I use what?

The reader is advised not to get too hung up on when to write sus, add or no. When devising your own symbols, my recommendation would be to not use "no" at all, and use "add" and "sus" just for triads with added/suspended notes (possibly also with seventh chords). In other words, try not to devise too creative chord symbols. The reason is that most common voicings of huge extended chords have one or two missing notes, without in any way lessening the impact of those sonorities. Go for the simple solution, if nothing else then for the fact that someone might very well need to read and interpret your chord chart as they go along. Seeing a creation like C9sus4add13(no5) will probably cause more confusion than it's worth.

Power Chords and Intervals

Power chords are usually not notated with chord symbols since they are normally found in riff-based music that is best written in tablature or staff notation. But some sources insist on providing symbols for them anyway. When you encounter the symbol C5, it is a power chord that lacks the characteristic third.

This principle can also be put into practice with other intervals that are not straight power chords, for instance C2 for a C–D dyad, or C4 for a C–F dyad. In the context of these chord analyses, sometimes other chord symbols like C6 or C7 have been written to denote intervals rather than the full four-note chords. Similarly, altered power chords use symbols like C−5 and C+5 without requiring the intervening third.

Alternate Chord Symbols

When perusing some predominantly older literature, one might run into chord symbols that use alternative systems. As these can often cause great confusion, I thought I might mention some of the alternate symbols.

Triads

The four established standard triads—major, minor, diminished and augmented—can be written Cmaj, Cmin, Cdim and Caug, respectively. This is internally consistent, but these symbols can easily be confused with others: Cmaj with Cmaj7 and Cdim with Cdim7. Cm can also be abbreviated Cmi.

Another method uses the so-called macro symbols, where the aforementioned triads are abbreviated C, C⁻, C° and C⁺, respectively. This is potentially very confusing, because an orphaned alteration sign generally refers to the fifth. The symbol C− could easily be interpreted as a C major triad with a diminished fifth.

Four-note and Extended Chords

In some works, minor and major chords, especially seventh chords, are abbreviated m and M, respectively. CM7 is then equivalent to Cmaj7.

Yet another way to abbreviate Cmaj7 is the Delta symbol: CΔ7.

The minor major seventh chord is frequently written Cm+7 or CmΔ7.

The symbol Cø7 is supposed to be a "half-diminished" chord, i.e. a diminished triad with a minor 7th. There are no half-diminished intervals, so the proper symbol is the more unambiguous Cm7−5.

The C7+9 "Jimi Hendrix chord" can sometimes be written C7−10, perhaps to underline the fact that an augmented second is enharmonically equivalent to a minor tenth/third.

Notes on Transcribing

If we take a basic C major triad and then add all the various combinations and permutations of (unaltered) extension notes, what to call each and every chord could be summarized something like this:

In practice, just about any of the chords marked with an asterisk are perfectly valid substitutions for the fuller 11 and 13 forms.