Abstract: A digital electronic musical instrument for synthesizing a musical waveform by computing high harmonics. The musical instrument includes a musical waveform generator, an overflow detection circuit and a data selection circuit. A musical waveform is preferably added at an adder which outputs an added musical waveform. This output added musical waveform is checked to determine if an overflow condition occurs. A data selection circuit receives the added musical waveform and establishes level limited data and non level limited data. The data selection circuit selects the level limited data upon occurrence of an overflow condition and selects non level limited data when no overflow condition exists.