.MU3 File Extension
File TypeMyriad Packed Musical Score
What is a MU3 file?
File created by Myriad musical notation software; saves sheet music as well as any digital audio data, but compresses the audio data with .MP3 or .OGG compression; differs from the .MUX format, which stores the instruments and sheet music, not the audio data.
NOTE: Myriad projects typically use the .MYR extension.