A sound source circuit is provided for a telephone terminal to reproduce chorus-effect imparted musical tones as incoming call sound or hold sound. Herein, original musical tone data .omega. c1 are slightly modified in pitches to produce musical tone data .omega. c2 with respect to a prescribed tone color. These musical tone data are periodically selected and synthesized together to form musical tone signals having a chorus effect, based on which the chorus-effect imparted musical tones be reproduced for the telephone terminal such as a portable telephone.