Abstract: A method and apparatus for shifting pitches of audio signals to achieve desired pitch relationships between the audio signals. Two or more audio signals are received. The audio signals may be in either a digital or analog format. One of the input audio signals is selected to be a reference signal. For each of the other audio signals, the pitch of the other audio signal is compared with the pitch of the reference signal to determine a relative pitch relationship. For each of the other signals, an adjustment is determined to bring the relationship to a desired pitch relationship. Based on the adjustment, the pitch of at least one of the audio signals is adjusted to achieve the desired pitch relationship between the audio signals.