I needed a clip like that. A midi converted to wav. We were basically going to use it for Karioka type purposes. A midi effectivly gets rid of all voice. Also, a midi can sound excellent for the right source. A piano or organ solo on a good sound card can sound absolutly perfect.
Trouble is, I could not find a single program to do the job for free. All the shareware demos would only record about 40 seconds.