is there a program that can do that?

[Semidevil]

I have this program, where that if it loads a midi file, it can seperate all the channels, and you are able to edit each and every instrument or a channel at a time....and kind of mess around with the midi file.

is there an equivilant for mp3s?

 

[mundane]

You could use a program like audacity to open the mp3, and edit the channels. Catch is there is usually only mono / stereo channels (not individual channels for each instrument). If you're looking to edit the mp3 file on an instrument-by-instrument basis, I think you're out of luck.

 

[Forsythe]

Editing mp3's pr. instrument is impossible. Midi is recoreded pr. instrument, mp3 is not, it's just boiled down together. Like a record.