Because I keep forgetting how to do this, and the obscure forum URL I have bookmarked for this is bound to go away sooner or later, here is how to convert a #midi to #wav data (which can then be encoded to anything you like using #ffmpeg; #mp3 in this example) with #timidity:

timidity -T 100 inputfile.mid -Ow -o - | ffmpeg -y -i - -ab 128k "outputfile.mp3"

Where the '-T' value is tempo percentage; 100 does nothing in this case, but 200 would double the tempo, 50 would halve it, etc.

The other part of the timidity toolchain is having the #freepats #soundfont installed, and configuring timidity to use it. (https://wiki.archlinux.org/index.php/Timidity%2B%2B)

I think most #linux distros have timidity/freepats packages. #audio