[krisneuharth]

Another HNer was working on something like this for rap: http://www.hiphopgoblin.com/

It is apparently not being worked on anymore but was focusing on mixtapes and such.

Edit: Found the project open-sourced on GitHub: http://github.com/zackster/hip-hop-goblin

[DTrejo]

A couple of my friends are working on a new and much improved version of it - there should be an ask HN thread about it in the next month.

I'm excited for them to release it :)