Tenshi no Shippo Chu!: Tenshi no Utagoe  

Tenshi no Shippo Chu!: Omnibus Tenshi no Utagoe, The Angels Singing Voice, Tenshi no Shippo Chu Special, Angel Tales Chu Special, Angel Tales Chu! Special, Tenshi no Shippo 2 Special, Tail of Angels Chu! Special

The special you're referring to is a collection of all the episodes from the season, with each character having their own unique song performed by their respective voice actor. This video showcases the individual stories of each girl and includes karaoke text at the bottom for viewers to sing along.