Anatomy of a Chord Symbol

Thumbing through a pile of sheet music on my desk, I notice that there are at least half a dozen different styles for chord symbols in use on those pages.  If I consider all of the variations of how one could notate the basic chord type, type of seventh used, and how raised and lowered notes are indicated, just using the forms that appear the music currently on my desk, there are 648 (!) different possibilities. And this doesn't take into account how multiple additions are presented, (i.e. linearly, stacked, stacked diagonally) or other things like suspended chords, altered 7th chords or polychords. No wonder some musicians get a bit confused at times.

There is no standard way of notating chords. I even have a chart for a well-known piece my jazz ensemble plays that has different notations for the same chord! How is an inexperienced musician supposed to make sense of such things?

Fortunately, regardless of the style, most chord symbols tend to have the same basic form, and figuring out what a chord is supposed to mean is usually straightforward.

Root and Type

The simplest chord symbols represent triads (or inversions thereof).

            

The four chord symbols above represent the four types of triads - major, minor, diminished and augmented. Note that all four start with a note name - the 'root' of the chord. (If this means nothing to you, you might want to read this post.) The root is always a capital letter, and the largest single character in the chord symbol.

The C major symbol has only the root specified. The minor, diminished and augmented chords have an additional 'modifier' to indicate the triad type. This is a fairly consistent convention when naming chords - if no modifier is given to indicate that the triad is minor, diminished or augmented, then the chord has a major triad. Some musicians, however, use a modifier to indicate major chords, usually "ma" or "maj" (in lower or upper case)

The modifiers for the other triad types vary, depending on whoever is writing the chords. Minor chords can be indicated with a lower case 'm', as shown above, or with a minus sign (–), or "MI" (usually in small caps, or at least smaller than the root).

Diminished chords will usually be indicated with a small circle (as above) or with 'dim'. Sometimes the minus sign (–) is used. As noted above, the minus sign is also used for minor chords, so here we find a potential source of confusion.

Augmented chords will generally be indicated with a plus sign (as above) or with 'aug'.

Occasionally you may come across music where diminished chords are indicated as minor chords with flattened fifths, and augmented chords are written as major chords with raised fifths.

Extensions

Beyond the basic triads, we get extensions to 7ths, 9ths, 11ths and 13ths:

The image above shows how the extension to a major triad are constructed and the corresponding chord names. Here are the equivalent minor extensions:

This brings us to the next aspect of a chord symbol - the number indicating the extension. This number appears after the modifier for the triad - the number may be the same size as the root letter and on the same baseline, or it may be smaller and raised, or maybe just raised. There is no one way, and different musicians/publishers do their own thing.
    
One particular variation to this arrangement is the distinction between two types of 7th - the minor or dominant 7th, which is 10 semitones above the root, and the major 7th, which is 11 semitones above the root. The minor/dominant 7th is the most commonly used, so no particular symbol is used to indicate this, and the extension number is all that is needed. The major 7th, however, is always indicated in some way, the two most common being either 'maj' or a triangle (∆) placed before the extension number.

Sometimes, in the case of a major 7 chord, the 7 is left off, as the presence of 'maj' or ∆ is considered enough to imply that the 7th is present in the chord. (But note that earlier I said that some musicians use 'maj' to indicate simply a major triad - another opportunity for confusion.)

The diminished 7th chord has a slightly different structure:

The 7th in this case is based on the diminished scale, and the diminished 7th (interval) is 9 semitones, not 10.  So Cdim7 (the name of the chord shown above) indicates a diminished triad with the diminished 7th added. You do not see further extensions to the diminished triad.

Alterations and Additions

Sometimes a note in a chord will be raised or lowered by a semitone. This is an alteration. The chord is notated as above, then the altered note is indicated after:

This is a 9th chord with a flattened or lowered 5th. As with extension numbers, the positioning of the alteration is not set, and may be on the same smaller, raised, etc.

Alterations may be indicated with sharps and flats, but also with pluses and minuses - yes, we've already seen those used for other things, so here is yet another instance where confusion can reign.

To make matters worse, on some music the pluses and minuses appear after the altered note rather than before it. (In fact, I have a piece at hand - a jazz standard - where the person who transcribed it has in some places used pluses and minuses before notes for alterations, in other places put the pluses and minuses behind the altered notes, and has also used the plus sign to indicated augmented chords! It's an absolute mess.)

Additions are notes added to a chord, but not as part of an extension. For example, we might add a 13th note to a major 7 chord, but as we are not added the 9th (or 11th) as well, this would not be a major 13 chord. So we write the name of the major 7 chord, then put the added note after:
    
Here we see two ways to indicate the added note - the first uses 'add', the second puts the added note in parentheses. Both ways are commonly used.

Sometimes the added note is not part of the normal scale for the chord, for example, a flattened 13th. If we add this note to our major 7 chord, we can simply append the added note without putting 'add' or parentheses, as there is no ambiguity about the extra note being an addition rather than an alteration:

A chord may have more than one alteration or addition:

Here there is both an addition (the flat 9) and an alteration (the flat 5). The two have been stacked in a column inside the parentheses. The same chord could have been written in a linear fashion: D7♭5♭9.

Omissions and Suspensions

Sometimes a specific note will be left out of a chord, e.g. we might omit the 5th from a chord with a flattened 13th:
    
The 'power' chord used in rock music consists of just root and 5th, so the common notation is, for example, Cno3. (The other common name for a power chord is a '5th' chord and the equivalent notation is, for example, C5, which is inconsistent with the way that extension numbers are typically used.)

Sometimes 'omit' will be used rather than 'no'.

A suspended chord will mean one of two things, depending on context. In pop and rock music (though it also crops up in other styles), we find 'sus4' and 'sus2' chords.
       
In these chords, the third is omitted and replaced with the 4th (e.g. Dsus4) or the 2nd (e.g. Asus2). The modifier 'sus' in these cases indicates a modification to the basic triad.

The other use of 'sus' comes from jazz, and is not (typically) followed by a number:
 
In this case, the meaning of 'sus' is to play a major triad one tone lower than the indicated root over that root. The 5th may or may not be played, and while the third is usually left out, occasionally it might be played as well. (Hey, it's jazz!) So E7sus would indicate a D triad played over a E, with possibly the B and/or G# included (or not).

Bass Notes

Sometimes a base note other than the chord root is used. The usual way to indicate this is to put the bass note after the chord symbol, separated by a slash:

Note, however, that this same format is also used for polychords (see next section).

Some Other Chords

Some commonly seen chords don't quite fit what has been described so far.

The 6th chord is very common. The meaning is clear - a triad (major or minor) with the 6th included. You could think of this as an extension or an addition, it really doesn't matter. D♭add 13 would have the same meaning, but the more compact form is the most common.

The 6/9 chord is also very common, especially in jazz, consisting of a triad with both 6th and 9th added. The usual notation is the 6 and 9 in a slanted fraction form, as shown above, but sometimes the 6 and 9 are stacked in a column, often (but not always) in parentheses. Sometimes '6add9' is written.

The 'half-diminished' chord may be indicated by a slashed circle, as shown. By 'half-diminished', what is meant is that the basic triad of this chord is a diminished one, but the 7th of this chord is a minor 7th (10 semitones above the root), not a diminished 7th (9 semitones above the root). This chord might appear with or without a 7 after the slashed circle, or might also be notated as  min7♭5, which accurately describes the structure of the chord.

Polychords, also known as polytonal or stacked chords, are where one chord is played over another. A well known example from classical music is the 'Petrouchka' chord from Stravinksy's ballet of the same name:


This chord could be written as a Cadd♯6♯9♯11, but also thought of as an F♯ chord over a C chord, and written as:
    or    
The first of these notations is exactly the same as the format for indicating bass notes. The second is clearer, but could take up more space vertically.

Occasionally on a score we come across problematic notations. For example, what is C4 supposed to represent? Does it indicate an added 4th, or a sus4 chord? Usually this has to be determined from the context. Occasionally it may be necessary to listen to a recording of the piece to identify what the chord is meant to be.

In a document I came across recently ("Standardized Chord Symbol Notation" by Brandt & Roemer, 1976), C4 was suggested as a notation for a type of chord used in jazz called a fourth chord. (You can read my explanation of fourth chords here.) But while fourth chords are fairly common in jazz, I have never seen such a notation used, and in fact such a notation misses the very point of what fourth chords are about.

Let's finish by examining a chord symbol (albeit a very unlikely one) and identifying the relevant parts:


The following diagram indicates the key points:


Using different styles for representing the triad type, seventh type and alterations, the same chord could be written as:

While the style might be different, the structure is essentially the same.

Chord Notation - Beyond Extensions

In this post, I want to look at chords that don't fit into the previous two posts.

Specifically, I want to examine the following:

• Suspended chords
• Fourth Chords
• Polychords

Suspended Chords

We come across suspended chords in two forms, one common in rock/pop music (though it also occurs elsewhere), the other mainly appearing in jazz.

The Suspended Fourth and Suspended Second chords

Consider the following two chords:

The one on the left is a C suspended fourth chord (Csus4). The one of the right is a C suspended second chord (Csus2). In both cases, we have replaced the 3rd with another note, either the 4th or the 2nd.

The effect of this is to create a chord that sounds like it's waiting to shift into something else. Changing the 4th (or 2nd) to the 3rd (major or minor) resolves the chord. This is actually a very old idea, musically, going all the way back to the Renaissance.

In modern usage, a suspended chord is not necessarily resolved in this way. Suspended chords may also included the 7th.

Suspended Chords in Jazz

The jazz approach to suspended chords is often a bit different to what was described above. As described by Mark Levine in 'The Jazz Piano Book', jazz musicians will play a major triad one tone below the root of the chord, e.g.

This is a Gsus chord. (Notice no specified 4th or 2nd.) We see in this example a G played by the left hand, and an F triad played by the right hand. Working from the G as the root, this chord has root, 4th, 7th and 9th. Remembering that the 9th is the same note as the 2nd, we see that this chord has no 3rd but the 4th and the 2nd. We could also notate this could as F/G (an F chord over a G bass). Dropping the 4th a semitone resolves the chord into a G7 (with added 9th).

If the 5th is included in the suspended chord, then instead of F/G, we have Dm7/G:


Another difference in the context of jazz is that sometimes the 3rd is included(!):

Jazz musicians do this to create a greater degree of dissonance to add interest to what they are playing.

Fourth Chords

The basic chords we looked at in an earlier post, along with their extensions, were formed by stacking notes in thirds (major or minor). But we can stack notes in fourths instead, and the resulting chords are quite interesting.

The diagram above shows a series of fourth chords, representing the different voicings achieved as we move the formation up a C scale.

The first chord can be recognised as an inversion of a C6/9 chord. Similarly, the fourth chord shown is an F6/9.

The second chord can be recognised as a Dm6/9, but we could also use it as a G13 chord (it lacks only the G from this chord).

The third chord is not so easy to identify, but can be played as a variety of Gsus. The same is true of the sixth chord.

The fifth chord contains all the notes of a G13 chord.

The seventh chord is the oddest sounding. Notewise, it is an F6/9 with an added ♯11. (In the 'Jazz Piano Book', Mark Levine calls this an F∆7♯4, but this is with the understanding that a 6/9 chord can be substituted for a major seventh chord.)

Polychords

A polychord can be defined as a chord over another different chord:

The notation shown above, with the names of the chords stacked vertically, separated by a line, is a common way of notating such structures. The combination of chords in this fashion produces interesting sounds, mainly through dissonance. Polychords are not often seen outside the jazz context.

The same two chords could be named in other ways. For example, the first could be interpreted as a C11 ♭9 ♭13; the second could be understood as a G13♯11.

Where polychords are indicated on a piece of music, the performer may not necessarily include all notes of each chord, allowing for interpretation of how the piece should sound.

Consider the following chords (taken from the piano part of a 1950s jazz standard):

We could notate the chords here (except the last, which is just an inversion of E7) as polychords:
A∆7 over B, A over Gm, D over A, F#m7 over D.

(On the piece in question, the chords are actually marked more simply as A∆9, B♭dim, Bm11, E7sus.)

Chord Notation - Beyond Sevenths

In a previous post I covered the basic ideas behind chords as they appear in Western music.

Across much of contemporary music, basic triads and sevenths cover the vast majority of chords used. (Some musicians/bands have never used anything else!) But beyond these, we find a rich palette of chords that occur in all types of music.

Ninths, Elevenths and Thirteenths

Typically, the nature of extended chords in Western music is one of adding additional notes to a triad at intervals of either a major or minor third.


The obvious thing here is that the numbers used to refer to the extensions are all odd. There's no mystery to this, - the 8th, 10th and 12th notes of the scale are just the root, 3rd and 5th which are already in the basic triad, and the 14th is the same as the 7th. The 13th note is the same as the 6th note of the scale, however, a 6th chord is not quite the same as a 13th chord, and we will look at it later.

You may have also noticed that in the thirteenth chord, the 11th (the F) is parenthesized. This is because the 11th is often omitted from a thirteenth chord (it can sound rather dissonant if included, but sometimes that may be the sound you want).

The same structures can occur with major sevenths rather than the dominant sevenths in the previous example:


Similarly, we can have 9th, 11th and 13th minor chords:

Additions

Apart from building up chords by stacking thirds (major and/or minor), we can construct chords which have closer or wider intervals.

Consider the following three chords:

The first of these is a major triad with a sixth added to it. Not surprisingly, we call this a sixth chord. We would write simply C6 for this chord.

The second chord has a 9th added to it, but no 7th. The lack of the 7th means that this is not a 9th chord, as described above, but an added ninth chord. We would write C add9.

The third chord has both the sixth and ninth added to the basic triad. Following our previous examples, a logical name for it would be a sixth added ninth chord, but as this is a commonly used chord, particularly in jazz, it is more often referred to as a 6/9 chord. Either C6 add9 or C6/9 is common written for this chord.

Here are a selection of other additions:

The first is a C7 chord with an added 11th (C7 add11).
The second is a Cmaj7 chord with added 11th and 13th notes (C∆7 add11,13).
The third is a C minor chord with added 9th (Cm add9).
The fourth is a Cm7 chord with added 13th (Cm7 add13).

Alterations

Apart from adding notes that appear in the scale for a chord, we can also sharpen or flatten notes in a chord:

The first chord shown above is a C9 chord. In the second, the 9th has been flattened. The rest of the chord is the same as a C7 chord, so this is seventh flat ninth chord - C7♭9.

Common alterations are raised (sharpened) or flattened 5ths and 9ths, raised 11ths and flattened 13ths.

You may wonder - what's the difference between having a raised 11th and a flattened 5th? In a chord with a flattened 5th, the unflattened 5th would not appear; in a chord with a raised 11th, on the other hand, the unflattened 5th is still part of the chord. Look at the following:

The first is a C7♭5 chord, the second a C7♯11 chord. (Notice that for the name of the second chord, we omitted the 'add', as we have already specified the extension - a seventh.)

Chords with these sorts of additions and alterations are very common in jazz and contribute to the overall sound of that particular genre of music. But they can also appear in pop, rock, blues, country and folk music, and can be readily found in classical music as well.

Chord Notation - Basics

Chord Notation - The Basics

Triads

Chord notation, as it appears in Western music,  is based on scales.


The main musical scale of Western music is the major scale, shown above for the key of C. Using each note in the scale as a starting point, we can construct a triad (three note chord) by combining it with the note two steps above it, and the note two further steps above:


Why two steps? Because these combinations are pleasing to the ear. Triads I, IV and V have a sound that it often described as 'happy'. Triads ii, iii and vi have a 'sad' sound. Triad vii has a tense, unresolved sound.

What triads I, IV and V have in common is that they share the same interval structure between notes. Between the bottom and middle notes is an interval of a major third, or 4 semitones. Between the middle and top notes is an interval of a minor third, or three semitones. We call these major chords.

Triads ii, iii and vi, on the other hand, have an interval of a minor third between the bottom and middle notes, and major third between the middle and top notes. These are minor chords.

Triad vii, the one with the unresolved sound, has a minor third between both bottom and middle, and middle and top. This is a diminished chord.

These chords are named by their bottom (root) notes, so:

• I = C major
• ii = D minor
• iii = E minor
• IV = F major
• V = G major
• vi = A minor
• vii = B diminished

In practice, musicians usually refer to major chords just by the root, so they will say "G" rather than "G major".

What about a triad that has a major third between bottom and middle, and middle and top? Here is such a chord:


We call this an augmented chord - note that it includes a note that does not appear in our scale.

Augmented chords have a 'floating' quality and, like diminished chords, sound as though they want to resolve to something else (a major or minor chord).

So we now have the basis of the four types of triads that typically appear in Western music - major, minor, diminished and augmented.

Inversions

Because the same notes are repeated in different octaves, it is possible to have the same three notes in different ways:

The above shows a C chord (that's C major) in three different positions - the same three notes are used (C, E and G), but in different octaves. These arrangements are called inversions. Notice that in the inversions, the intervals between notes have changed, and we now have intervals other than major or minor thirds.

Seventh Chords

Using the triads as a starting point, we can construct other chords involving more than three notes.

Our basic C chord consists of the first, third and fifth notes of our C scale. We can add the seventh note of our scale to form a seventh chord:


If instead we started at the G in our scale, treating it as the first note of the scale and combined it with the third, fifth and seventh, we get this seventh chord:

The sounds of these two chords are noticeably different - the difference lies in the interval between fifth and seventh. In our first seventh chord, built on the C root, the fifth and seventh are a major third apart, but in the second seventh chord, built on G, the fifth and seventh are a minor third apart.

We call the first chord a major seventh chord, in this case, C major 7 (usually written on music as Cmaj7 or C∆7).

 The second is still a major chord (because the basic triad of root-third-fifth is major chord), but in this case we call it a dominant seventh chord. Why 'dominant'? Because the fifth note of a scale is called the dominant. Often when referring to dominant seventh chords, the word 'dominant' is omitted. So in the case of our second chord above, we would call it G7 (and write it that way as well).

So from a major triad, we get two types of seventh chord, the major seventh and dominant seventh.

Going back to our scale again, our minor chords were build from D, E and A. Constructing seventh chords from the triads with those roots, we find that they all have an interval of a minor third between the fifth and seventh:

So these are minor seventh chords, D minor 7,  E minor and A minor 7, and would be written as Dm7, Em7 and Am7.

Going back to scales for a moment, Western music also has a minor scale, shown here for the key of A minor.

Here we see two versions of the scale for A minor. The first version shows the notes of the scale as per the key signature. In the second version, the seventh note of the scale has been raised a semitone. Raising the seventh like this has been seen in Western music since the time of Bach - it changes the final step from seventh to root from a tone to a semitone, so that resolution from seventh to the root sounds more finished; the chord built on the fifth note of the scale becomes a major chord rather than a minor one, and moving from a major chord on the fifth to the minor chord on the root again has a more finished sound.

The seventh chord built on the root of this scale has a major third between the fifth and seventh:

We call this a minor major seventh chord. (We would write Am maj7 or Am∆7.)

Finally, we will look at the diminished seventh chord:

This chord is based entirely on intervals of a minor third. For this example,  the chord would be called C diminished 7 and written Cdim7 or Co7.

The interesting thing about diminished seventh chords is that different diminished seventh chords are inversions on one another. For example, Ddim7, Fdim7, A♭dim7 and Bdim7 are all the same chord!

There is also a chord often referred to as a half-diminished seventh:

This is also based on the diminished triad, but the seventh is a major third above the fifth rather than a minor. Another, perhaps better, description for this chord is a minor seventh with a flattened fifth. The example above might be called a "C half-diminished 7", or a "C minor 7 flat 5". In written form, the most common notations are Cø7 or Cmin7♭5.