An automatic playing system is independent of acoustic pianos, and is designed to perform music tunes expressed by sets of MIDI music data codes on the acoustic pianos; since the acoustic pianos have their own individualities, control parameter table, which were prepared through experiments on a standard piano, are not optimum for most of the acoustic pianos due to the individualities: the automatic playing system can tailor the control parameter tables defining relation between the magnitude of driving signal and the MIDI velocity and relation between the magnitude of driving signal and time lag from the supply of the driving signal and the collision between the hammers and the strings for each sort of acoustic pianos before the automatic playing so that the automatic playing system reproduces the music tunes at high fidelity regardless of the sort of acoustic pianos.