I got stuck, and anything I’ve found so far is shareware.
I’m not sure exactly what you mean, but Cakewalk may be what you are looking for.
Unfortunately I don’t know of any program that does a straight conversion from Midi to Mp3.
I use Audacity to record while I’m playing my Midi files. It does a pretty good job.
QuickTime, at least the Pro version, will open any MIDI file and will let you export as AIFF, as MP3, or as WAV.
Timidity (with a GM SoundFont file - Chaos is pretty good and big) + Audacity
All free.
Timidity renders the midi file to a WAV file (it may go directly to MP3 now - I see it now does ) using the Soundfont to provide the instrument source - Audacity can convert WAV to MP3.
Si
Note that the MP3s will be a lot bigger than the MIDIs with no gain in quality: A MIDI file is just a sequence of ‘notes’, whereas an MP3 actually records all of the sounds those notes make when played. It’s the difference between sheet music and a CD.
Converting a MIDI file to an MP3 is a matter of changing to a format that can be played on more devices reliably and with a defined measure of quality. Most computers don’t have very good instrument banks for playing midi, so they suck (as my daughter just said). Mobile phones that play midi are even worse. So rendering a MIDI file to WAVE (or MP3) is usually about finding a decent MIDI soundfont to get something that sounds realistic for what you want to use it for.
Si