Music appplication

I am trying to code an application which will act as a virtual karaoke app. I want to compare the users voice to the original singer voice with this HQ soundcloud downloader and i do not know on what basis can i do that, Is this even possible? I want to design this to generate user scores based on how close their pitch reaches to the original singer.

Better ask this at stackoverflow.com

Sometimes asking on Codeforces too gets useful responses. But yeah, I can’t think of a better place than http://stackoverflow.com/ as @vijju123 suggested.