Reference · 02

Sus, Add, Dim & Alt

Every suffix after a chord letter answers one question: which note is swapped out or added, and where. Read them that way, and sus, add, dim, aug and alt stop being a memorization list.


A plain major or minor chord is built from the root, 3rd and 5th. Every symbol below is a small, specific edit to that base: a suffix either replaces the 3rd, adds an extra tone without disturbing the triad, or bends the 5th and 7th. Once you know which one a symbol does, you don't need to memorize each chord shape separately.

SymbolWhat it doesExample
sus2Replaces the 3rd with the 2ndCsus2 = C–D–G
sus4Replaces the 3rd with the 4th — tends to resolve back down to the 3rdCsus4 = C–F–G
add9Adds the 9th on top of the plain triad, with no 7thCadd9 = C–E–G–D
dim / dim7Flattens the 3rd and 5th (dim7 also flattens the 7th twice)Cdim7 = C–E♭–G♭–B♭♭
aug / +Raises the 5th a half stepCaug = C–E–G♯
altA dominant 7th chord whose 9th, 11th and 13th are freely altered (♭9, ♯9, ♯11, ♭13)G7alt = G–B–D♭–F + altered tensions
What actually shows up on a worship chartsus2, sus4, and add9 appear constantly, usually on the chord right before a chorus lands. dim7 and alt are rare — mostly passing chords or jazz-influenced reharmonizations — so it's fine to recognize them by sight rather than reach for them when writing your own charts.
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Chord Tensions Aren't Chord Tones