We describe a novel system for tennis performance analysis that allows coaches to review games and provide detailed audio-visual feedback to tennis athletes. The basis for our system is a network of low-cost IP cameras surrounding the tennis court. Our system exploits the output of several visual analysis modules, including the tracking of players and the tennis ball, and the extraction of player silhouettes for 3D reconstruction. A range of intuitive tools within the interface allow tennis coaches to add 2D and 3D annotations to live video, view play from multiple perspectives, record audio commentary and compute game statistics in real-time. The result is a video file that can be used to provide personalised feedback to the players or for use as a teaching resource for others. While we focus on tennis in this work, we believe our system can be generalised to other sports and allow a range of non-professional sports clubs to provide high-quality feedback to their athletes.