Abstract: An effect adding system for use in Karaoke performance applications is provided which, when one person sings, singing with different height from that of the actual singing, or singing with different timing from that of the actual singing, is automatically carried out to yield, in part, the same effect as if a chorus, duet, round, or the like is performed by a plurality of persons. In one embodiment, the effect adding system accomplishes this by means of pitch conversion and/or delay of the aural input signal in response to pitch conversion and/or delay information deriving from stored performance information for a particular musical composition.