Audio

What is a .mxl file?

A .mxl file is a Compressed MusicXML. This is an audio format. Confusingly, this extension has been used by 3 different formats over the years — they're all listed below.

This extension has been used by more than one format

3 different formats have claimed .mxl over the years, so two files with the same extension aren't necessarily the same kind of thing.

How to open a .mxl file

VLC plays almost every audio format ever made.
Audacity opens it for editing.

The registry records this extension against Compressed MusicXML, MOXCEL, Compressed MusicXML, so software from that family is the most likely match.

How to convert a .mxl file

Export as .mp3 from Audacity or VLC for maximum compatibility.

MIME type

When a .mxl file travels over the web, servers label it with this MIME type:

application/vnd.recordare.musicxml

What's a MIME type?

The technical record

For archivists, developers and the merely curious: these are the PRONOM registry entries for .mxl.