chou eshi ten ~if no gakkyoku sekai ten~
An annual exhibition managed by Niconico under its "Choukaigi" (超会議) artist platform that runs during the last full week of April. Its theme is "what would the world look like if the artists were different?", where artists are given a list of themes by VOCALOID producers based on their songs and must reinterpret them in their own styles.
It features approximately 100 artists, with 4 each drawing 1 of the 25 songs available.