This study proposes to use the analysis of physiological signals (electroencephalogram (EEG), electromyogram (EMG), heart beats etc) to control sound synthesis algorithms in order to build biologically driven musical instruments. A real time music synthesis environment and algorithms are developed to map these signals into sound. Finally, a "bio-orchestra", with two new digital musical instruments controlled by the EEGs and EMGs of two bio-musicians demonstrated this concept with a live concert on stage