The Three Sirens are not conventional musical instruments but autonomous, self learning robot musicians. They are not controlled by humans. Artificial neural networks control every aspect of the robot’s activities. This means that the authorship for their music does not belong to any living being (no predefined material or musical knowledge is available to the system), all musical material is generated by self organizing learning processes in an improvising manner.
Link to Video of guitar-bot Aglaopheme's solo.
(via Autonomous Mutations)