In this paper we present a real-time system for morphing two voices in the context of a karaoke application. As the user sings a pre-established song, his pitch, timbre, vibrato and articulation can be modified to resemble those of a pre-recorded and pre-analyzed recording of the same melody sang by another person. The underlying analysis/synthesis technique is based on SMS, to which many changes have been done to better adapt it to the singing voice and the real-time constrains of the system. Also a recognition and alignment module has been added for the needed synchronization of the user's voice with the target's voice before the morph is done. There is room for improvements in every single module of the system, but the techniques presented have proved to be valid and capable of musically useful results.