Musical tone generating apparatus with parameter controller for changing

Abstract

A musical tone generating apparatus is provided for an electronic musical instrument. The apparatus comprises a musical tone signal generating device and a parameter controller. The musical tone signal generating device generates a musical tone signal characterized by a tone parameter whose value is supplied from the parameter controller. The parameter controller comprises a target value generator and an interpolation device, which operate independently. The target value generator generates a target value of the tone parameter to the interpolation device, and the interpolation device interpolates between a present value of the tone parameter and the target value, so that the present value is renewed consecutively. The interpolation device generates an interrupt signal to the target value generator when the present value reaches the target value, so that an operation of the target value generator is interrupted then the target value generator operates to generate a new target value to the interpolation device in response to the interrupt signal. The parameter controller changes a characteristic of the musical tone signal such as a frequency characteristic or amplitude with respect to a lapse of time based on the present value of the tone parameter.