Are you looking specifically for songs that mention the words 'elf', 'elves', 'elfin' etc, because, in traditional song at least, there is no difference between an elf and a fairy, apart from their linguistic origins (Germanic and Celtic respectively). In 'Folklore in the English and Scottish Ballads', Wimberly more or less treats them as the same.

This is not surprising, given that, I would guess, by the time most of the ballads would have been composed, English had pretty much settled down into what we speak today, and it's doubtful that, in England and Scotland, the linguistic origins of 'elf' and 'fairy' would have been considered important.

This being the case, would you also be seeking songs about fairies? This would lengthen your list considerably.

How about 'The Wee Wee Man'?