The Heart Chamber Orchestra - HCO - is an audiovisual performance. The orchestra consists of 12 classical musicians and the artist duo TERMINALBEACH. Using their heartbeats, the musicians control a computer composition and visualization environment. The musical score is generated in real time by the heartbeats of the musicians. They read and play this score from a computer screen placed in front of them. Custom-made software analyzes the data and via different algorithms it generates the real-time musical score for the musicians, the electronic sounds and the computer graphic visualization via 2 projectors in the space.