According to a Twitter post made by Quincy Jones III today, Scratch: The Ultimate DJ's turntable controller includes Mp3 functionality.
Here's the tweet:
"The scratch video game also has a real mp3 turn table with a functional fader, just like the real thing... will keep you posted on updates."
What this means is that it will be an actual instrument without the need of modifications.
We'll keep you posted if you like.