What is the easiest way to convert .gpx scores to .mp3 audio format?
Converting Guitar Pro 6 Music Scores directly to MP3 Audio Files (.gpx to .mp3 conversion) is certainly possible and quite straightforward, even though your options are somewhat limited.
Use the latest version of Guitar Pro, which allows users to import GPX tablatures and export them in MP3 format.
A multi-track editor and music composer for guitars
A free cross-platform music notation software