Patent ID: 8530736

Claim:
A musical tone signal synthesis method of synthesizing a musical tone signal based on performance information, the musical tone signal simulating a sound generated from a musical instrument having a three-dimensional structure including a string that undergoes vibration and a main body having two string supports, between which the string is stretched, the vibration traveling from the string to the main body through at least one of the string supports, the musical tone signal synthesis method comprising: a string model calculation process of inputting an excitation signal based on the performance information to a closed loop having a delay element that simulates delay characteristic of the vibration propagated through the string and a characteristic control element that simulates a variation in amplitude characteristics or frequency characteristics associated to propagation of the vibration, and calculating first information representing a force of the string acting on at least one of the string supports on the basis of a cyclic signal circulating in the closed loop and representing the vibration of the string; a main body model calculation process of calculating second information representing, on modal coordinates, a displacement of each vibration mode of the main body or representing an nth order derivative (n=1, 2, . . . ) of the displacement with time, on the basis of an equation of motion that represents the vibration of the main body caused by the force of the string represented by the first information; and a musical tone signal calculation process of calculating the musical tone signal on the basis of the second information.