Direct MIDI to MP3 comes with a 30 day trial and costs $29.95 to purchase. However, if you promote the software on your website or blog (see the Pistonsoft site for details) they will send you a free key to register your software.
- drag your midi files to the converter window (limit of 5 with the trial version)
- click the Convert button
- choose a folder to output files
- (optional) choose audio output settings
- press the Start button