Suspended vs Add Chords vs Extensions (9, 11, 13) on Piano

A suspended chord replaces the third with a 2 or 4, an add chord keeps the triad and adds a 2, 4 or 6, and an extension (9, 11, 13) adds those same notes on top of a chord that already contains a seventh.

Video lesson by Jason Zac · Intermediate · 25 min

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Sus chords, add chords and extended chords are often confused because they use the same extra notes: the 2, the 4 and the 6. In this lesson Jason Zac from Nathaniel School of Music explains how each type is built on the piano, how it sounds and how you can use it. It suits pianists who know their major and minor triads and want richer, more deliberate chord choices. All examples use A major (A C# E) and A minor (A C E).

1. Suspended chords: replace the third

A suspension removes the third (major or minor) and replaces it with another note.

• Asus4 = A D E. The third is replaced by the perfect fourth.
• Asus2 = A B E. The third is replaced by the major second. You can find the 2 a whole step above the root, a whole step below the major third, or a half step below the minor third.

Because there is no third, there is no such thing as a minor sus2 or major sus4. The same sus chord can stand in for either the major or the minor chord. Major and minor triads feel stable; a sus chord feels like it is hanging in the balance, asking where to go next. Try moving major to sus4 and back, or minor to sus2 and back.

Suspended chords also let you explore different bass notes in the left hand while the right hand pivots between sus2, sus4 and the triad.

More suspended colours

• Sus2 plus 4: root, 2 and 4 with the fifth left out (A B D). Add the fifth for flavour if you wish. It has a fusion feel.
• Add the minor seventh (G) and you get A B D E G, a five-note pentatonic sound that is very ambient.
• 7sus4 = A D E G. This can resolve to the dominant A7 (A C# E G), which in turn resolves to the tonic, D. Here A is the V of D.

2. Add chords: keep the triad and add a note

An add chord keeps the third and simply adds a note, so it usually becomes a four-note chord.

• Aadd2 = A B C# E. Very ambient. It is sometimes called add9, because a 9 is just a 2 (for C, the 2 or 9 is D).
• Aadd4 = A C# D E. Not a sus4, because the third stays.
• Add #4 = A C# D# E. A rarer, Lydian sound.
• Triad with a flat 2 gives a Phrygian sound.
• A6 = A C# E F#, a major triad with a major sixth.
• Major with a flat 6 (or sharp 5) = A C# E F, a mysterious sound.
• Am6 = A C E F#, and minor with a flat 6 = A C E F.

Add chords sound good as blocks and also arpeggiated. They work well in country and ballad playing. Jason demonstrates mixing add2 and add4 chords while playing Amazing Grace. Take any song you have chords for and decide, chord by chord, whether you prefer the add2 or the add4 colour.

3. Extensions: 9, 11 and 13 need a seventh

A 9 is a 2, an 11 is a 4 and a 13 is a 6, played up the octave. You only use these numbers when the chord already has a seventh (major or minor). Since 1, 3, 5 and 7 make up the chord, the remaining notes, 2, 4 and 6, are counted beyond the octave as 9, 11 and 13.

• Amaj7 = A C# E G#. Add B for a 9, D# for a #11, F# for a 13.
• A7 = A C# E G. The 9 is B, the 11 is D, the 13 is F#.
• Am7 = A C E G, extended with B, D and F#.

An easy voicing trick

Play a G major triad (G B D) in the right hand over A in the left. You get the flat 7, 9 and 11 for a sophisticated A11 sound.

How to practise

1. Pick a triad and cycle triad, sus4, sus2, triad, listening to the tension and release.
2. Keep a sus shape in the right hand and try different bass notes.
3. Play a song's chords with add2, add4 or add6 colours and choose what you like.
4. Build 7th chords and add 9, 11 and 13, then try the triad-over-bass voicing.

Questions about this lesson

What is the difference between sus4 and add4?

A sus4 removes the third and uses the perfect fourth instead, for example A D E. An add4 keeps the third and adds the fourth, for example A C# D E.

Is add2 the same as add9?

Yes, they are often used interchangeably because a 9 is the same note as the 2. For C the added note is D in both cases.

When should I call it a 9th chord instead of add9?

Use 9, 11 and 13 when the chord already contains a seventh, major or minor. Without a seventh, the extra note is an add2, add4 or add6.

Is there a minor sus2 chord?

No. A sus chord has no third, so it is neither major nor minor and is simply called sus2 or sus4. It can replace either a major or a minor chord.

Practise it

• Voicing RoomA hands-on lesson room for piano chord voicings.
• Chord TreesStart from a note and explore related chords, inversions and voicings.
• Piano classes at Nathaniel School of MusicLive online or in Bangalore, with a teacher.
• All free music apps40 practice tools for harmony, rhythm, ear training and more.

Related lessons

• 5 Beautiful Piano Chord Fills to End Any Rhythm PatternFive simple piano chord fills you can play at the end of a bar or cycle are inversion switching, chord-tone arpeggios on the same hand shape, added notes such as add 2, add 4 and add 6, diatonic neighbouring thirds around the chord's third, and octave melodies that land on a chord tone of the next chord.
• 5 Simple Ways to Make Your Chords Colourful Without ExtensionsYou can make simple major and minor triads sound colourful on piano, without sevenths or jazz extensions, by using five voicing techniques: static fifth chords, add2 and add4 chords, slash chords, spread voicings, and quartal or quintal voicings.
• Chord Trees: Build Any Chord From Any Root on PianoAny single note belongs to exactly six major and minor triads: as the root of a major and a minor chord, the fifth of a major and a minor chord, the major third of one major chord and the minor third of one minor chord. For C these are C, Cm, F, Fm, Ab and Am.
• Half-Diminished vs Fully Diminished 7th Chords on PianoA half-diminished chord (m7b5) is a diminished triad plus a minor seventh, such as D F Ab C, and works best as the ii in a minor ii-V-i, while a fully diminished seventh chord is a stack of three minor thirds, such as D F Ab B, and behaves like an unstable dominant that can resolve to four major and four minor keys.