Scarborough Fair is a very old song, according to Wikipedia dating back at least to 1670, and probably much earlier. Here are three versions from the mid-sixties.
The first from Martin Carthy was released in 1965, on his first album:
The second,from Marianne Faithfull, was released in 1966 on the album North Country Maid:
The third, from Simon and Garfunkel, was released later the same year, and of the three is by far the best known: