How to play Csus4 (C Sus4) on Guitar

Csus4 is the C sus4 chord. It is built from 3 notes — C, F and G — which sit at the root, perfect fourth and perfect fifth above the root C. Written as a formula that is 1P – 4P – 5P. Those intervals, not the note names, are what give the chord its character: move all of them to a different root and you still hear a sus4 chord.

Csus4 on guitar is an open shape — 2 strings ring open while 3 are fretted, the shape spans 3 frets, 1 string is muted and should not sound — damp it with the underside of a fretting finger. Open strings do a lot of the work here, which is why this shape sounds fuller than the effort it takes. Arch your fingers so each one lands on its fingertip — a finger leaning flat will deaden the open string next to it, and a single muted string is the most common reason a beginner's chord sounds wrong when the fingering is in fact correct.

This chord has no third, so it is neither major nor minor. That ambiguity is the point: it sits comfortably under a melody that moves between the two, which is why shapes like this are so common in riff-based and folk playing. With only the triad and no added seventh, the chord is stable and finished-sounding, which makes it a natural place for a phrase to land.

Csus4 belongs to 5 major keys, including C major, where it is the I chord, F major, where it is the V chord, Bb major, where it is the ii chord, Eb major, where it is the vi chord and Ab major, where it is the iii chord. That is the practical reason to learn it: a chord that is diatonic to several keys turns up constantly, and knowing which degree it occupies tells you what tends to come next. A I chord in C major most often moves toward the tonic, so practising Csus4 in the context of C will teach you more than practising it in isolation.