By clicking the option that says 'export to mp3'?

ShunNakamura, I was suggesting that Xaven (the user) should use cdex. Not you, as it doesn't have any midi capabilities that I am aware of

I suggest using google. The very first hit was http://www.pistonsoft.com/midi2mp3.html which is a [n apparently] unrestricted 30 day trial.

I just ran one of Nik0tine's midis through there, Little song in G minor, and it sounds fine:]
(fine in that it sounds like a midi in mp3, not a midi played with real instruments.)