mp3 to mxl conversion is typically searched by users looking for a way to turn ordinary MP3 audio to a music sheet in MusicXML format. This might be doable with proper software, but usually follows steps of first turning the MP3 to MIDI and then making a music notation based on it, although most tools automate it. Harmony Assistant is a popular tool for this, but you can certainly find more.
Updated: August 24, 2023