I’ve always liked that sound, especially the fourth [pickup position on a Strat]. When I was a kid, that was my favourite sound on the guitar; it’s even, it’s smooth, it has chimeyness but it still has bass. It’s the most colourful selection on the Strat." So said John Mayer to us back in 2010, and that leads us to what he considers to be the perfect accompaniment for that kind of go-to tone.
“Sort of in the centre of the fretboard… the one, the two and the five. I think that’s sort of my signature," he says of the three-note inversions that form a key part of some of his most popular songs.
These triads (three-note chords) above are the kind of approach Mayer is talking about. And there is a slight ambiguity to them at times; a sus2 is neither major nor minor and an Emaj7 could be seen as a C#m9 if played over a C# root.
Whatever mood you're hearing, they'll sound great with a clean tone.