Sus & Add Chords

In a sus chord the 3rd is not played (it is "suspended").

• In a sus4 chord (often just sus) the 3rd is replaced by a 4th.
• In a sus2 chord you play a 2nd instead of the 3rd.

Since sus chords have no 3rd, they are neither major nor minor, but form their own category.

sus9 is just a shorthand for 7sus4(9) - a sus4 chord with a 7th and a 9th.

The 9 represents the same note as the 2 in the sus2 chord. The number in the chord symbol does not specify where the tone has to be played on the fretboard. It just helps to identify the other intervals of the chord. 9 means: "there is also a 7th", 2 just means: "the 3rd is missing".

In an add chord a note is added to the basic triad. While C9 also contains a 7th - it's a shorthand for C7(9) - there's no 7th in Cadd9.

Thus, Cadd9 is a C major triad (C E G) with an added 9th (D).

On the staves you see the chords in their theoretical base form. In a Csus4, for example, E is replaced by F. In practice you can place that F anywhere on the guitar's fingerboard. You might play it one or two octaves higher, and you may double notes in the chord; the same freedom applies to the other chord tones.

Root on A string: example chord shapes in C

Here are five progressions in different keys. First, a version with major/minor (including some m7 and maj7) chords; the variations (button) then replace some with sus and add chords.

add2, add4

Intervals of the basic triad or seventh chord are numbered up to 7 (e.g., 1 m3 5 7 for m7, or 1 3 5 6 for a sixth chord). For additional tones an octave is added to the interval (only in the chord symbol!), which results in a 9 instead of 2, an 11 instead of a 4, a 13 instead of a 6.

If you encounter add2, it usually means add9; add4 usually means add11. In sus2/sus4 it's different because 2/4 replaces the 3rd and thus becomes part of the basic chord. If the composer wants a specific voicing (e.g., the 9 exactly a 2nd above the root), they should write the exact notes on staff or tab, since chord symbols do not specify voicing or octave.

Both suffixes are technically correct. In practice, unlike major, minor chords can almost always take a 7th (e.g., Dm7 instead of Dm). On guitar, a voicing with a 9 may simply run out of string or finger for the 7th. Therefore it's often simpler (and just as appropriate) to write m7(9) (short: m9) or m7(11) (short: m11) and omit the 7th in the voicing if needed.

Similar for sus2: instead of a plain major chord you can often play add9 (if you like the sound). Omitting the 3rd in add9 yields sus2. In practice, sus2 is often a variant of add9 or even of a plain major chord, so consider whether to write sus2, add9, or just major (and leave freedom to the player).