Mechanical vibrations have typically been used in the performance domain within feedback systems to inform musicians of system states or as communication channels between performers. In this paper, we propose the addi- tional taxonomic category of vibrational excitation of mu- sical instruments for sound generation. To explore the va- riety of possibilities associated with this extended taxon- omy, we present the Oktopus, a multi-purpose wireless sys- tem capable of motorised vibrational excitation. The sys- tem can receive up to eight inputs and generates vibrations as outputs through eight motors that can be positioned ac- cordingly to produce a wide range of sounds from an ex- cited instrument. We demonstrate the usefulness of the proposed system and extended taxonomy through the de- velopment and performance of Live Mechanics, a compo- sition for piano and interactive electronics
