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. 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—and the other way around: putting the proper abbreviation on a chord you just invented!
Chord symbols are built on uppercase musical letters that indicate the root note. Unless otherwise indicated, they are assumed to be in root position. (Henceforth I will use the root C for consistency.)
Unless otherwise stated, chords contain a major third and are to be considered major chords. The suffix "m" indicates a minor chord. This applies no matter how many notes are added and/or altered.
The only exceptions are diminished seventh chords and suspended chords, both of which will be discussed momentarily.
The fifth is assumed to be perfect unless specifically altered by a "+5" or "−5" suffix.
The Basic Triads
With very few exceptions, all chords with four or more notes are based on the symbols for the four plus two basic triads. For reference, those symbols are given here:
- Major triad (root, major third, perfect fifth): C.
- Minor triad (root, minor third, perfect fifth): Cm.
- Diminished triad (root, minor third, diminished fifth): Cm−5.
- Augmented triad (root, major third, augmented fifth): C+5.
- Minor augmented triad (root, minor third, augmented fifth): Cm+5.
- Major diminished triad (root, major third, diminished fifth): C−5.
A dominant seventh chord is abbreviated C7, since the absence of "m" denotes a major third, and the 7 a minor seventh (see the article on chord theory for an explanation why). A major seventh chord is abbreviated Cmaj7.
The quality of the third has no bearing on the seventh. A C minor seventh chord is abbreviated Cm7. Change the seventh from minor to major and it's Cmmaj7.
The full diminished seventh chord (diminished triad + diminished seventh) is abbreviated "dim7". The chord contains a minor third even if this isn't specifically stated in the symbol.
Any seventh chord can have its fifth altered, creating symbols like Cm7−5, C7+5, Cmaj7−5, etc. The altered note is always written last in the symbol, for clarity.
The addition of a sixth to a major or minor triad is abbreviated simply "6". (However, see 13th chords below.)
A ninth chord is a seventh chord that has been extended by the addition of a (major) ninth. The symbol for a ninth chord is simply C9. However, behind that 9 lurks the assumption that the chord also contains a (minor) seventh.
Any "m" or "maj" suffixes in the symbol always and exclusively apply to the third and seventh, respectively. Cm9 is a C minor triad with a minor seventh and a major ninth. Cmaj9 is a C major triad with a major seventh and a major ninth. C9 is a C major triad with a minor seventh and a major ninth. All three chords contain major ninths.
The ninth can be altered in two ways. It can be minor, which is written −9, or augmented, which is written +9. For clarity, the seventh is always clearly written out: C7−9, C7+9, etc.
Note that the augmented ninth is enharmonically equivalent to the minor tenth/third. There can be no m7+9 chords.
If you also consider the possibility of altering the fifth, there can be quite a large number of variations on the ninth chord.
An eleventh chord is abbreviated C11 and adds a perfect 11th to the ninth chord. That's right: this is a six-note chord that assumes the presence of a (minor) seventh and a (major) ninth in addition to the basic underlying triad.
In a chord such as Cm11, the "m" still refers to the third, and in Cmaj11, the "maj" refers to the seventh. (The 11th obviously cannot be major, since it is a perfect interval.)
An 11th can appear in its perfect form (11) or augmented (+11). A diminished eleventh is enharmonically equivalent to a major tenth, i.e. a major third.
The fifth and ninth can still be altered, which creates interesting looking chord symbols in extreme cases: Cm11−9+5. However, 11 chords is also when you start to run out of musical space. There can be no m11+9 chords because there are no m7+9 chords (see above). Also, an augmented 11th and a diminished fifth cannot appear in the same chord; these two notes are also equivalent.
The basic C13 chord symbol adds a major 13th to the basic C11 chord. This is a seven-note chord that assumes the presence of a (minor) seventh, a (major) ninth and a (perfect) eleventh.
The presence of "m" still refers solely to the third, and any "maj" only applies to the seventh. Other chromatic variations must be written with alteration signs.
Gotcha! There are no 15th chords, because the 15th is a double octave. The largest chord possible by the orthodox stacking of thirds is the 13th chord. It contains all seven scale degrees.
Suspended chords are chords where the third has been temporarily replaced by a major second, a perfect fourth or an augmented fourth. These are written Csus2, Csus4 and Csus+4, respectively.
Remember: the suffix tells you which scale degree to substitute for the third.
Since the third is missing from these chords, obviously there can be no minor or major suspended chords. However, the suspension can be freely combined with other scale degrees, most commonly sevenths. These are abbreviated 7sus4, etc.
The add symbol is used to indicate that a ninth or eleventh has been added to a triad, or an eleventh to a seventh chord, 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. The symbol C9 automatically assumes the presence of a minor seventh as well.
- Cadd11 is a C major triad with the addition of a (perfect) 11th.
- C7add11 is a C11 shape that lacks the ninth.
Some sources write add2 instead of add9, and add4 instead of add11. For practical purposes, these can be thought of as interchangeable. The added notes tend to be voiced pretty high up in the chord anyway, for clarity.
Add13 chords are, as far as is practical, to be considered as variants of sixth chords, e.g. C6add9, C6add11, etc.
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.
If another note than the root is the lowest note in the chord, it must be indicated in the chord symbol. The chord symbol is written as usual, followed by a slash and then the bass note:
- C/E means a first-inversion C major triad; with E in the bass.
- C/G means a second-inversion C major triad; with G in the bass.
- C7/Bb is a third inversion chord, only possible with seventh chords; it is a C7 chord with Bb in the bass.
If the bass note is not indigenous to the chord, it is often referred to as a polychord. e.g. G/E or C/F#.
It can be a stimulating exercise to try to analyze the chord from the standpoint of the bass note rather than the root note. Many polychords tend to be chord synonyms rather than polychords. If you play a G major triad with an E as a bass note, you get an Em7 chord. E minor seventh with G in the bass is a G6 chord, and so on.
Extended chords can also be thought of as true polychords. A C11 chord consists of the pitch classes C, E, G, B flat, D and F. The top three notes constitute a B flat major triad. Even if the transcriber does specify two triads to be played simultaneously, they can often be squeezed into the system of chord symbols.
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.
The Confusion Zone
Unfortunately, chord symbols are nowhere near as standardized as musical notation. There are several ways to make abbreviations, and many of these methods are not only inconsistent with themselves, but also incompatible with others and could potentially give rise to great confusion.
The method I present in this article is one that most of my sources tend to agree on. By implication, we could be approaching something akin to a standard for chord symbols. But there is still older and/or inconsistent material out there, so you need to be aware of the pitfalls that could arise.
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.
Yet 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 yet another abbreviation standard assumes that an orphaned alteration sign refers to the fifth. Cm−5 is then written Cm− and C+5 is written C+. The symbol C− (see above) could then easily be construed as a C major triad with a diminished fifth.
Sometimes, the plus and minus signs can be substituted for musical sharp and flat signs (#/b), but in my personal opinion, the plus and minus signs are easier to read.
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
The preceding section has hopefully inspired you to be consistent. This section is more about being flexible.
At the end of the day, chord symbols are at best vague hints of the composer's intentions or the transcriber's interpretations. I state very squarely that a ninth chord has to contain a seventh, an eleventh chord both a seventh and a ninth. I jump through hoops to explain the meaning of add, sus and no. Like these are laws that cannot be broken. Well, it's called music theory for a reason, namely that it is separate from music.
The most perfect example of what I'm trying to illustrate is the 13th chord. As you've already learned, it is a seven-note chord containing all seven degrees of the scale. Do you know what? It is therefore impossible to fret on a six-string guitar. Any voicing you see is inevitably going to be incomplete—yet you rarely see a transcriber or the editor of a chord dictionary resort to tongue-twisters such as C9add6 (no5). No, the voicings that are most frequently used omit at least two notes without lessening the impact of the chord.
The larger extended chords are massive sonorities, and who is really going to be able to tell if you fret an 11th chord without the fifth, or a ninth chord without the third?
I had great fun making the following table, because it was a good mental exercise to analyze all the possible combinations. Technically, I suppose you could regard it as an instruction book on how to name chords. Realistically, see it as an academic exercise:
|Component notes||Chord symbol|
In actual music, any of the chords marked with an asterisk would be a perfectly acceptable voicing of an 11th or 13th chord. The important part isn't to squeeze in all of the extension notes as long as you hit some of them. It should also be noted that C7/6 and C6add9 are long-established substitute-13 voicings for guitarists.