Add sound effect(background sound) while recording

I'm developing an application for record user voice. I want when recording, user can tap on screen to add some sound effects, like a short song or clapping.This sound also recorded with user voice. And when i play the recorded sound, also get user voice and sound effect. How can i do that? I try to search something but my English is not good so maybe the search key is not correct, not get more results. Thanks for your help.