Q: When I try to use iTunes to convert a MIDI file into AAC, I get an error message -50. I have scoured the Internet for various file conversion programs, but nothing seems to actually work to convert MIDIs; I always get odd errors, or files that just turn out as silence. Do you know of any way I can successfully convert these files into any iPod-compatible format?
A: The issue is that MIDI files aren’t actually a sound file – they’re more like text-based “digital sheet music” that instructs your computer what to play. Because of this, a MIDI file will sound different on different computers, depending on their sound cards’ MIDI engines and/or the software being used. Considering this very unique nature of MIDI audio files, it’s perhaps not very surprising that waveform-encoding algorithms don’t know what to do.
However, you’re not entirely out of luck. There are programs available for Mac and Windows which, although not necessarily intended for MIDI conversion, are designed to record any audio at all that your computer generates.
On the Mac, Ambrosia’s WireTap Pro is our absolute favorite. It intercepts nearly any audio that either leaves through your Mac’s speakers, or comes in through its Line-In or Microphone ports, and can record and encode directly to AAC audio on the fly.
On the PC, we’d recommend HighCriteria’s $12 TotalRecorder Standard Edition. While not as pretty or feature-packed as WireTap Pro, it certainly will suffice for capturing and encoding MIDI files. Try it out!