The Shirareta Sekaiseries features several songs that I've listed below. The last song is Japanese and the upper two are in a language I created for the Elven Kingdom. I've added translations to each song, so that you can read what it's actually about. Please enjoy! 🙂
Maimi Lilílon (The Return of Layhar, p. 236-237; The Choice of Amar, p. 112)
Tali Tali (The Choice of Amar, p. 155-156)
Daiji na Aniki 大事な兄貴 (The Choice of Amar, p. 224-225)
English 
Nederlands