MusicXML is an XML-based file format for representing Western musical notation. The format is open, fully documented, and can be freely used under the W3C Community Final Specification Agreement.
MusicXML was invented by Michael Good and initially developed by Recordare LLC. It derived several key concepts from existing academic formats (such as Walter Hewlett's ASCII-based MuseData and David Huron's Humdrum). It is designed for the interchange of scores, particularly between different scorewriters. MusicXML development was managed by MakeMusic following the company's acquisition of Recordare in 2011. MusicXML development was transferred to the W3C Music Notation Community Group in July 2015.
Version 1.0 was released in January 2004. Version 1.1 was released in May 2005 with improved formatting support. Version 2.0 was released in June 2007 and included a standard compressed format. All of these versions were defined by a series of document type definitions (DTDs). An XML Schema Definition (XSD) implementation of Version 2.0 was released in September 2008. Version 3.0 was released in August 2011 with improved virtual instrument support, in both DTD and XSD versions. Version 3.1 was released in December 2017 with improved support for the Standard Music Font Layout (SMuFL). The MusicXML DTDs and XSDs are each freely redistributable under the W3C Community Final Specification Agreement.
As of October 2021[update], MusicXML is supported to varying degrees by over 260 notation programs. These programs include:
Like all XML-based formats, MusicXML is intended to be easy for automated tools to parse and manipulate. Though it is possible to create MusicXML by hand, interactive score writing programs like Finale and MuseScore greatly simplify the reading, writing, and modifying of MusicXML files.
The textual representation listed above is verbose; MusicXML v2.0 addresses this by adding a compressedzip format with a .mxl suffix that can make files roughly one-twentieth the size of the uncompressed version.
^Hewlett, Walter B. (1997). "Chapter 27: MuseData: Multipurpose Representation". In Selfridge-Field, Eleanor (ed.). Beyond MIDI: The Handbook of Musical Codes. MIT Press. pp. 402–447. ISBN0-262-19394-9.