What is an MXL file?
An MXL file is the compressed form of MusicXML file format that is an open standard format for exchange of digital sheet music. Plain text MusicXML files are large in size and the use of such files as a sheet distribution format was affected with the large file size. This issues was treated with MusicXML 2.0 by introducing the MXL file format that compresses the files enough to reduce the file size similar to that of original MIDI files. Recommended media type for MXL files is application/vnd.recordare.musicxml.
MXL File Format
MXL files are stored as ZIP compressed XML files with .mxl file extension. MXL files are compressed with the DEFLATE algorithm as specified in the RFC 1951.
Key Characteristics of MXL Files
| Characteristic | Description |
|---|---|
| File Extension | .mxl |
| Format Type | Compressed archive (ZIP) containing MusicXML data. |
| Core Technology | XML (Extensible Markup Language) with ZIP compression. |
| Primary Use Case | A stripped-down, optimized derivative of the MIDI standard. |
| Advantage over MusicXML | Significantly smaller file size and single-file convenience. |
| Software Support | Widely supported by all major music notation software platforms. |
| Editable | Yes, but typically requires conversion/unpacking to a native format within the software. |
MXL vs. Proprietary Formats: Why It Matters
While software like Finale and Sibelius use their own native formats for full editing capability, the MXL format serves a different, critical purpose: interoperability. You would use a native .MUSX file to work exclusively in Finale, but you would export an MXL file to send that same score to a colleague who uses Sibelius. It is the lingua franca of the music notation world, breaking down the barriers between software ecosystems.
MXL File Structure
Each MXL file has a ZIP-based XML format that must have a META-INF/container.xml file which describes the starting point of the MusicXML version of the file. There is no corresponding .xsd file defined for the MXL file format.
A simple container.xml file has contents as follow. This example is taken from Dichterliebe01.mxl file available on the MakeMusic web site.
<?xml version="1.0" encoding="UTF-8">
<container>
<rootfiles>
<rootfile full-path="Dichterliebe01.musicxml"
media-type="application/vnd.recordare.musicxml+xml"/>
</rootfiles>
</container>
In this example, the element is the document element. The element can contain one or more elements, with the first element describing the MusicXML root. A MusicXML file used as a may have , , or as its document element.
FAQ
Q1: What is the difference between an MXL and a MusicXML file?
A: An MXL file is a compressed ZIP archive that contains a MusicXML file, making it much smaller and easier to share than the raw, uncompressed .xml version.
Q2: Can I open an MXL file in MuseScore?
A: Yes, MuseScore and other major notation programs like Finale, Sibelius, and Dorico can natively open and import MXL files directly.
Q3: Is the MXL format better than PDF for sheet music?
A: Yes, for editing; while a PDF is a static image, an MXL file contains editable musical data, allowing you to change notes, instrumentation, and other elements.
Q4: How do I create an MXL file?
A: You can create an MXL file by using the “Export” or “Save As” function in your music notation software (like Finale or Sibelius) and selecting the “MusicXML” or “MXL” format option.
Q5: Why is my MXL file not opening in another program?
A: This is often due to one program using an older version of the MusicXML standard; ensure both your exporting and importing software are updated to their latest versions.
