While a Windows Media Audio (WMA) file generally contains high-quality audio (good enough to listen to a song on), a MIDI (Musical Instrument Digital Interface) file contains instructions, not actual sound. Those instructions can play back a very basic version of a song, either using a computer or cell phone’s internal synthesizer or using a MIDI-compatible instrument like a keyboard. Free software exists to convert WMA files into smaller, MIDI instructional files for embedding on websites or using as basic ringtones.
