月と虎落笛のインソムニア (Tsuki to Mogaribue no Insomnia)

Background
The song was first uploaded on November 26th 2008, and is ke-ji's 6th original Vocaloid work. It's overall his most notable song and have achieved Nico Hall of fame (exceeding 100,000 views), with 150,000 views to date. The song features a "12-choir Len", which is somewhat ke-ji's signature on composing songs (12 choir of the same Vocaloid).

This folk celtic song at first just an instrumental song, however ke-ji later made it into a singable song as "Insomnia of the Winter Wind Whistle and the Moon". It's later featured on the album "VOCALOID Minzoku Chou Kyoku shu", fully remastered with the Appends.

The lyrics to the song could be interpreted in various ways, for ke-ji himself stated that it's written / inspired by classical literature. It tells a story of the moon, the snow, nature.