E Major 6th
6
0 - 4 - 7 - 9Major + major 6th
About E Major 6th
E6 is E major with a C♯ added, and on guitar it is one of the fullest-sounding chords available: six strings, several of them open, and a sixth that turns the loudest chord on the instrument into something that sounds settled rather than declamatory.
The notes
E, G♯, B, C♯. The C♯ is the major sixth, and it can be fretted on the A string at the fourth fret or the B string at the second, depending on the voicing.
The same four notes read from C♯ give C♯ minor seventh — the relative-minor equivalence that every sixth chord carries, and the reason E6 can stand in for C♯m7 when the bass supplies the difference.
The chord is also unusually forgiving of voicing: because E is the lowest note available, the sixth can sit almost anywhere above it without the chord losing its identity.
On the fretboard
The open shape modifies standard E by moving one finger, and the result keeps all six strings sounding. The swing voicing on the middle strings at the seventh fret is tighter and mutable.
Because E is the key the instrument resonates in, this chord rings longer than its equivalents in other keys — a practical difference that matters when it is the final chord of a piece.
Where it shows up
As a final chord in blues and rockabilly in E, and as a tonic colour in swing. Early rock and roll used it constantly, and the sound dates a recording as clearly as the drum tone does.
It also appears in Hawaiian and country playing, where the sixth is a default rather than an ornament and the whole idiom rests on it.