Open Opus provides free, open data and software for the classical music industry. We're running three projects now: the Open Opus database, an open API for works and composers; Concertmaster, a free classical music front-end for Spotify; and Concertino, a free classical music front-end for Apple Music. All three projects have their source code - and data - freely available on GitHub and everyone is invited to join in! We strongly believe in open software/data and in open collaboration projects. Our goal is to allow the growth of self-organized communities around classical music metadata and streaming.