Sixth as a parrot

A slippery customer, this'un. Slippery, because you can play it almost anywhere. Finger an E major shape, then add the sixth note on the B string. Play it as an open E major sixth, and it sounds pleasantly unresolved; slide it up one fret (to the third), play it again leaving the open E strings ringing, and it gets all tense and nervous. Try it as well at frets 5, 7, 9, 10 and 12, after which it turns back into E6.