A method in accord with certain implementations involves, at an audio input, receiving a time domain audio signals; at one or more digital signal processors: converting the time domain audio signal to a frequency domain representation containing at least a fundamental frequency component, modifying the frequency domain representation to produce a modified frequency spectrum, converting the modified frequency spectrum to a modified time domain audio signal; and outputting the modified input signals as an output signal. This abstract is not to be considered limiting, since other embodiments may deviate from the features described in this abstract.

A movement actuated tone effects system is provided for manipulating the electrical signal of an electric instrument by moving the electrical instrument in relation to a set of reference axes. A movement actuated tone effects unit is positioned within the electric instrument or within an effects cartridge attached to the electric instrument via a cartridge receiver. The movement actuated tone effects unit includes a motion sensor unit, a processor, a tone effects circuit, and a power source, wherein the motion sensor unit measures the motion of the electric instrument and generates electrical signals directed to the processor. The processor analyzes the electrical signals, determines the appropriate tone effect to apply, and then directs the tone effects circuit to produce the desired tone effect. The movement actuated tone effects unit may further include an integrated speaker, a signal converter, a transmitter, and a device terminal.