There is not, there wasn't, and there probably won't be such a converter.
I know midi files, I have created a whole bunch of commercial materials in this format for a well-known Polish seller.
MP3 files are sound recordings, the sum of sound compiled into one bundle, while MIDI is a set of commands controlling the device playing them, the same MIDI file will sound different in a professional instrument, in a worse one, Rolland has different sound features than Yamaha, or Korg, and it will sound completely different on a computer without a special emulator installed, literally like a greeting card.
No most intelligent converter can extract from the total record of individual instruments and convert them to one of sixteen tracks using one of the 128 sounds of the MIDI standard, because it simply will not recognize and assign them. Conversely, there is no problem there are great players that convert MIDI to MP3, Wave etc., but you can't do it this way. Once I found something like that, but the result was a two-track clang of the basic piano sound on one track.
