The Young May Moon has two origins. It is an English, Jig and Morris Dance Tune and it was popular in the 19th century as a jig for country dances in South Scotland. The tune is in use
as accompaniment for a single step dance in the North‑West (England)
morris dance tradition, and (as "New May Moon") appears in a
Yorkshire MS collection of the mid-19th century.
It is also an Irish Air. Thomas Moore's title for his song set to Turlough O'Carolan's air "Planxty Peyton." The melody appears as “Irish Air from Robin Hood” in Thompson’s Hibernian Muse of 1786 (No. 38).