Elfenlied
"Elfenlied" is the conventional title of a 1780 poem by Goethe, and of a later poem by Eduard Mörike.
Goethe's poem was written in 1780, in a letter sent to Charlotte von Stein, without a title, but introduced by Die Elfen sangen "the elves/fairies sang"; the title "Elfenlied" were only set in editions of Goethe's collected poems. Goethe's poem is Romantic, invoking the image of a fairy-dance under the impression of a moonlit night.
It was set to music many times, e.g. as "Elfenliedchen" by Julius Kniese, as "Elfensang" by Erich J. Wolff and as "Elfenlied" by Alexander Zemlinsky.
Mörike's poem was written at some point between 1826 and early 1828. It is humorous, its premise being a pun on Elf, the German word both for "elf" or "fairy" and "eleven":
It describes an Elfe awakened one hour early for the fairy-dance, at eleven o'clock instead of at midnight, due to mistaking the watchman's calling out of the eleventh hour for the calling of the "Elves" to the fairy-dance.
Still half-asleep, the Elf mistakes glow-worms sitting on a stone wall for the lit halls of the fairy-hall and, trying to look in, bashes his head against the stone.
The poem was set to music by Hugo Wolf in 1888.
Hugo Wolf also composed a separate choral piece called "Elfenlied", in this case an adaptation from words in Shakespeare's A Midsummer Night's Dream.