Question: What is a sus2 chord?
A sus2 chord replaces the third of a triad with the second, creating an open, ambiguous sound that sits between major and minor.
Take C major: C–E–G. A Csus2 is C–D–G. The D (second) displaces the E (third). Because there's no third, the chord has no major or minor quality — it's neither. That ambiguity is the whole point. It sounds unresolved, waiting.
Sus2 chords are often used as a passing voicing between a major chord and its relative minor, or held as a deliberate harmonic stasis. On guitar, because of the open strings and the way the instrument is tuned, sus2 voicings often sound very open and ringing.
The sus2 is one half of the suspension family — sus4 (replacing the third with the fourth) being the other. Both sit outside traditional major-minor harmony.
