"Wild Mountain Thyme," sometimes called "Will Ye Go, Lassie, Go" is a Scots/Irish song derived from a traditional 18th century air. The contemporary version uses lyrics by the Scottish poet Robert Tannahil, first published in 1822. The best known arrangement is usually credited to Francis McPeake of Belfast (including a notation in Bob Dylan's copyright records) in the early 20th century. Surprisingly, it was first recorded only in 1957, by McPeake's nephew (according to Wikipedia), also named Francis, though it sounds much older and seems like it should have been long before then. There isn't much variation in the arrangements below, but the melody is always memorable. There are two clips of the McPeake family at the bottom of this post.
This is one of the few up tempo versions:
Francis McPeake III and Francis McPeake IV
McPeake Family, 1960
The Byrds do a nice version but you have to capo the 8th fret.
There were lots of videos for this song, so I didn't include any audio clips in the main post.
But here is the Byrds version: https://youtu.be/IEwqhaikDmg
Other audios suggested to me include Dylan and Baez: https://youtu.be/1Ag2i6Xs_zw
And Bert Jansch: https://youtu.be/Y6kQ2uxkws8