御祭騒ぎ(Omatsuri Sawagi / Festival Uproar) is the sixth doujin album by PolyphonicBranch. It was released at THE VOC@LOID M@STER 16. It features the vocals of GUMI and Miku and one track sung by an utaite. The CD comes with a 12 page booklet with illustrations. Album's official page is located on PolyphonicBranch's website and the crossfade can be seen on Nico Nico Douga. It can be ordered from Amazon.