The Complaints Choir project invites people to complain as much as they want and to sing their complaints out loud together with fellow complainers. The process contains workshops, public performances and video documentation. We organised the first choir in Birmingham followed by the Complaints Choirs of Helsinki, Hamburg-Wilhelmsburg, St. Petersburg, Copenhagen, Tokyo, Chicago, Teutonia and Singapore. The documentation of the nine choirs form a 4-channel video installation. In 2006 the project went "open source" when we published the "9 easy step method to organize a complaints choir" on our website. Since then over 100 DIY complaints choirs have been organised all over the world.