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.