With whom WERE YOU last night under the pale moonlight. (no second with)
The most frustrating grammar inconsistency I encounter is the switch from first to third person in traditional songs. I don't know if it's a result of someone cobbling different versions together into a cohesive tale, or some traditional narration switch about which I am ignorant. What I do know is that it drives me bonkers, and until I know the reason behind it I am loathe to change the wording.
It happens often in the "broken token" songs. By example: "I boldly stepped up to her, asking what greived her." and "I" "I" "I" for the majority of the tale. It suddenly turns to the third person singular for the denouement: "He fell into her arms; he could stay no longer." Same guy, but he abandons his narrative role without warning.