How to play Asus4 (A Sus4) on Guitar

Asus4 is the A sus4 chord. It is built from 3 notes — A, D and E — which sit at the root, perfect fourth and perfect fifth above the root A. 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.

Asus4 on guitar is an open shape — 2 strings ring open while 3 are fretted, the shape spans 2 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.

Asus4 belongs to 5 major keys, including C major, where it is the vi chord, G major, where it is the ii chord, D major, where it is the V chord, A major, where it is the I chord and F 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 vi chord in C major most often moves toward the tonic, so practising Asus4 in the context of C will teach you more than practising it in isolation.