How to convert .mp3 audio to .mg9 format.
Converting MP3 Audio Files directly to Band-in-a-Box Songs (.mp3 to .mg9 conversion) is possible, even though it is not a conversion in the proper sense.
Your only option is using the original software, Band-in-a-Box, which allows users to import/load MP3 audio files in order to generate MG9 song files.