Collected by Bob Copper in the 1950s, from Jim Swain of Angmering in Sussex. The words and music can be found in Bob’s book Songs and Southern Breezes, and you can hear Jim Swain singing the song on The Voice of the People Volume 10. I first heard the song on Shirley Collins’ 1974 LP Adieu to Old England.
I was surprised to find that this song shares the same Roud number as ‘As Broad as I was Walking‘. There’s little to link them on the surface, and a Roud number search of the Take Six Archive suggests that collected versions are either like ‘As Broad…’ or like ‘Banks…’ but not both. So while Mrs Webb’s ‘The Modest Maid’ is obviously a version of ‘Abroad as I was walking’, other songs such as Moses Blake’s ‘Nancy’ or Moses Mills’ ‘Twas Down in the Valley’ are clearly related to ‘Banks of the Mossen’.
Down in Yonder Valley - broadside from the Bodleian Collection
The same seems to be true of ballads on the Bodleian site: Harding B 17(196a) – ‘Modest Maid’ is without doubt a precursor of ‘Abroad as I was walking’ (in fact the words as sung by Mr Johnson seem to have changed very little from the broadside version); and Harding B 17(78b) – ‘Down in Yonder Valley’ seems to show how ‘Banks…’ started life.
But on a discussion on the Tradsong list Steve Gardham – quite an expert in these matters – suggested that both songs had a common ancestor, in the shape of
18th century broadsides which showed they were the same song called Beautiful Nancy… An Evans printing is in the Madden Collection, but you can view a Pitts version slightly later, called ‘Down in Yonder Valley’ on the Bodl site, Harding B17 (78).
The Madden Collection, unfortunately, has not been made available online (come on Cambridge!) so I’ll have to take Steve’s word for it.
Finally, this song has been referred to under a variety of titles: Banks of the Mossen, Mossem, Mossom, Mossing… but Mike Tristram, in the same Tradsong discussion, says
‘Mossen’ by the way in my understanding is a saxon plural ie ‘mosses’, rather than the name of a river, in other words it is ‘mossy banks’ good for lambs and love, rather [than] riverbanks.
The Banks of Sweet Mossen
A Folk Song a Week 
