the musical tone synthesizing apparatus simulating the wind instrument synthesizes a musical tone signal to thereby generate a musical tone corresponding to the wind instrument tone . herein , the musical tone synthesizing apparatus contains one or more stages each including a bi - directional transmission circuit and a junction . in each stage , the progressive wave signal is delayed by the predetermined delay time and transmitted to the junction . the junction multiplies the signal by first coefficient , whereby the result of multiplication is transmitted to the next stage . the junction also multiplies the progressive wave signal by second coefficient , whereby the result of multiplication is fed back to the prior stage . the first and second coefficients are changed over according to an operation of a tone hole to be provided in the wind instrument . thus , the musical tone of the wind instrument can be simulated with simple circuit or software .