Chord symbols tell you the root of the triad, the quality of the triad, any extensions to the triad, and any non-root bass note.

Chord symbols don't reference a specific key. Instead, symbols are always assumed to be a certain quality unless otherwise indicated:

Triads are assumed to be major.

Sevenths added to the triad are assumed to be minor.

All other extensions and added tones are assumed to be major/perfect.

Alterations are shown through sharp and flat symbols, or through plus and minus symbols. Both systems are prevalent in the real world; when writing your own charts, pick one system and stick with it consistently. This textbook will use the sharp/flat system of showing alterations.

[](https://viva.pressbooks.pub/app/uploads/sites/12/2019/08/lead-sheet-components.png) Example 1. There are four components to a chord symbol: 1) the root of the triad, 2) the quality of the triad, 3) the presence of extensions beyond the triad, and 4) the bass note.

There are two systems of shorthand for discussing harmony used in this textbook: chord symbols and Roman numerals. Chord symbols are also sometimes called “lead sheet symbols” because you will find them on lead sheets, which are jazz scores that typically notate only a melody and these chord symbols.

Chord symbols can pack a lot of information into a few letters. A complex symbol is given in Example 1, with annotations to show the various possible components of a chord symbol.

Basics of Chord Symbols

Triads

Chord symbols are based on the major triad as the norm. If you see nothing but a note name as a chord symbol, this means to play a major triad. Other symbols are added to indicate other triad qualities, as summarized in Example 2.

Example 2. Chord symbols for triads.

Notice that there are several ways to represent each non-major triad quality. This is because chord symbols were created along the way as jazz developed and were never completely standardized. The symbols in Examples 2 and 3 are not comprehensive, but you can likely decode other variations based on the ones here. It's good to be aware of all the possible ways of representing these different triad qualities, but stick to one method for yourself. In Examples 2 and 3, the symbols used in this textbook are given first.

Seventh chords

The most common addition to a triad is the interval of a seventh. An added seventh is indicated with the Arabic number 7 written after the root, superscript.

As with the triad, the numeral 7 by itself indicates a default quality: a minor seventh. Alterations to the symbol indicate other possibilities, resulting in the seventh-chord symbols summarized in Example 3:

Note: because triads are major by default and sevenths are minor by default, the symbol C7 indicates a dominant-quality seventh chord (major triad + minor seventh).

This table only shows the five traditional seventh-chord qualities, but others are possible, such as m(maj7), aug7, and more. Again, these tables are not comprehensive, but when you encounter an unfamiliar symbol, you should be able to use your knowledge of basic symbols to figure out what it means.

Bass notes

In much of jazz and pop, the bass note is the root of the chord. (Bassists may improvise around other notes, rather than strictly staying on the root of the chord, but this wouldn't affect how the harmony is written down.) For this reason, chord symbols are assumed to indicate root position chords unless otherwise indicated.

If the bass note should be something other than the root, this is shown with a slash followed by the letter name of the bass note. For example, C/E means to play a C major triad with an E in the bass.

Significantly, the bass note does not need to be a member of the chord! C/F♯ would indicate to play a C major triad over an F♯.

Extensions

[](https://viva.pressbooks.pub/app/uploads/sites/12/2019/08/extensions.png) Example 4. Adding more thirds beyond the seventh produces ninths, elevenths, and thirteenths.

Jazz harmony often involves not only playing the notes explicitly indicated by the chord symbol, but also adding upper extensions. The term extension comes from the idea of extending the stack of thirds that creates harmonies. The seventh is the most common triadic extension, but jazz often makes use of higher extensions—stacking more and more thirds onto the basic triad results in the ninth, eleventh, and thirteenth (Example 4).

Interval size

You may notice that ninths, elevenths, and thirteenths are just compound versions of seconds, fourths, and sixth, respectively, so why use the more difficult-to-conceptualize compound intervals, instead of just calling these intervals seconds/fourths/sixths? There are two reasons:

The presence of an extension in a chord symbol implies the presence of all other extensions below it as well. So, an eleventh chord is not just a triad plus the eleventh—it's a triad plus an eleventh, ninth, and seventh.Although all the extensions below the highest extension are implied, they are not necessarily played. In fact, usually all the possible notes are not played, and some of the extensions between the highest and the seventh are omitted. The differences between what is notated, what is understood, and what is actually played are discussed more in the chapter on Jazz Voicings.

Extensions are often voiced (played) above the other chord members. In other words, in actual performed music, the extension really sounds a thirteenth above the root, not a sixth (for example).

Interval quality and alterations to extensions

While the default quality of the seventh is minor, extensions and additions are assumed to be major (ninths and thirteenths) or perfect (elevenths) unless otherwise indicated. The chord in Example 4, then, is simply a C13 chord: all the extensions are majo