mgu to ly conversion is probably searched by users that are looking for a way to turn Band-in-a-Box MIDI song (.mgu) into a music score/notation sheet in LilyPond format (.ly).
LilyPond does not support MGU format, but other programs do. MuseScore is most likely your best choice in this matter as it support large number of MIDI formats as well as music notation formats.
Updated: September 20, 2023