A lot of them are names of Welsh and English villages and towns - guess the composer/plagerist likes the sound of them. At least one I know of was named for the town it was written in. Vaughn Williams plageruised a lot of Irish tunes and gave them English names because a) the Irish gaelic was to him, unpronouncable and b) because when he was composing and collecting, Ireland was still a land deeply troubled. To have anything to do with Ireland or Irish things was not considered politically correct.

LTS