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Community & Business Groups

Music Notation Community Group

The Music Notation Community Group develops and maintains format and language specifications for notated music used by web, desktop, and mobile applications. The group aims to serve a broad range of users engaging in music-related activities involving notation, and will document these use cases.

The Community Group documents, maintains and updates the MusicXML and SMuFL (Standard Music Font Layout) specifications. The goals are to evolve the specifications to handle a broader set of use cases and technologies, including use of music notation on the web, while maximizing the existing investment in implementations of the existing MusicXML and SMuFL specifications.

The group is developing a new specification to embody this broader set of use cases and technologies, under the working title of MNX. The group is proposing the development of an additional new specification to provide a standard, machine-readable source of musical instrument data.

w3c/musicxml w3c/mnx w3c/smufl

Group's public email, repo and wiki activity over time

Note: Community Groups are proposed and run by the community. Although W3C hosts these conversations, the groups do not necessarily represent the views of the W3C Membership or staff.

final reports / licensing info

date name commitments
MusicXML Version 3.1 Licensing commitments
SMuFL 1.3 Licensing commitments
SMuFL 1.4 Licensing commitments
MusicXML 4.0 Licensing commitments

Chairs, when logged in, may publish draft and final reports. Please see report requirements.

Publish Reports

Co-chair meeting minutes: May 25, 2023

(Apologies for the late posting of these minutes.)

In-person meeting, MOLA Conference Tech Fair, June 2, 2023

Our next in-person meeting is scheduled for this Friday, 2 June 2023. If you are able to join us in person at the Hanns Eisler School of Music in Berlin, we look forward to seeing you there. Otherwise, please join us via Zoom.

Meeting ID: 843 5670 2243
Passcode: 170077

The meeting is at 1330 UTC / 1430 BST / 1530 CEDT / 0930 EDT / 0630 PDT on Friday 2 June.

The agenda for the meeting is as follows:

  • Introduction to the W3C Music Notation Community Group
  • MusicXML 4.1 status update
  • SMuFL 1.5 status update
  • MNX status update
    • Reasons for switching to JSON
    • The role of microformats in MNX
    • Milestones towards 1.0
  • Lightning presentations from community members
  • Open discussion


Adrian has finished the conversion of the main MNX specification to reflect the new JSON syntax. There are a few dark corners remaining to be updated, but the bulk of the work is done; all of the examples are now in JSON, and the page comparing MNX to MusicXML now uses JSON for all of its comparisons.

The next step is to open some issues with the various questions that Adrian had to grapple with in the process of performing the conversion. The most interesting question arising is concerning styles: styles have two components, classes (which allow you to define a named style that can be applied to any object), and styling based on element names. The problem with the latter is that, of course, the new JSON version of MNX has no named elements: instead, it uses anonymous objects. Adrian proposes that to achieve this we will probably need to define an enumeration of item names that can be used to identify and locate items of particular types.

Adrian also plans to update the mnxconverter to output JSON in the near future.

Next co-chairs’ meeting

The next co-chairs’ meeting will be on Thursday 8 June 2023.

Co-chair meeting minutes: May 9, 2023

In-person meeting, Friday 2 June 2023, Berlin

A quick reminder that we are planning an in-person meeting at the MOLA Conference Tech Fair at the Hanns Eisler Musikhochschule in Berlin on Friday 2 June at 3.30pm. We would love to see as many community members as possible attend the meeting. If you are planning to attend (either in-person or online) please complete this form:


Adrian has continued to migrate the descriptions of the old XML elements to the new JSON key/value pairs, but the work is still not complete. As mentioned in the last meeting, Adrian is collecting some questions along the way for issues that will need to be raised for community approval, and he will post those at the conclusion of the migration work.

The discussion concerning the elimination of microformats from the MNX specification is still open at #293 and further feedback from the community is welcomed. At the moment, the co-chairs are satisfied that nobody has yet expressed strong dissent to the proposal to remove microformats, but we recognise that myriad specific issues will need to be addressed.

Next meeting

The next co-chair meeting is scheduled for 25 May 2023.

Co-chair meeting minutes: April 25, 2023

In-person meeting, Friday 2 June 2023, Berlin

A quick reminder that we are planning an in-person meeting at the MOLA Conference Tech Fair at the Hanns Eisler Musikhochschule in Berlin on Friday 2 June at 3.30pm. We would love to see as many community members as possible attend the meeting. If you are planning to attend (either in-person or online) please complete this form.


Adrian has continued to work on the JSON version of the specification. The page that compares MNX to MusicXML has been updated to refer to the JSON key names rather than XML element names. The remaining work is to complete the migration of the XML element descriptions to the JSON equivalents.

Myke led a discussion about the use of microformats in MNX, with the general thesis that using microformats for important data types like time signatures, note pitch, note duration, etc. may not ultimately be desirable for MNX. Although these are useful in terms of making the data more compact and human-readable, there are many potential disadvantages to using microformats, including:

  • Too distant from the goal of making data encoding in MNX amenable for a native format
  • Brittle and hard to expand in future
  • They don’t reveal the underlying data type: a time signature represented as a string like “4/4” doesn’t explicitly reveal that a time signature consists of (at least) a numerator and a denominator

The co-chairs agreed in principle that we should avoid the use of microformats in MNX and remove the ones that are currently specified. Adrian pointed out that the move to JSON is what makes this a viable option, since JSON is more compact than XML: creating richer data types in XML would be considerably more verbose overall. Myke has prepared a discussion in GitHub to summarise the co-chairs’ proposal and to gather feedback from the community.

Next meeting

The next co-chairs’ meeting will be on 9 May 2023.

Co-chair meeting minutes: April 18, 2023

In-person meeting, MOLA Conference, Berlin, 2 June 2023

We are looking forward to seeing as many community group members as possible at our in-person meeting at the MOLA Conference in Berlin on Friday 2 June 2023. Adrian and Daniel will be present and will be participating in a panel discussion along with representatives of other music software manufacturers immediately before our meeting, and we would love to see you there.

Registration to attend the MOLA Conference and the Tech Fair closes this week, on 21 April 2023, so please don’t delay if you intend to come along.

We would also love to have an idea about how many people plan to attend, so if you are going to attend, either in-person or online, please complete this form. We will share more details about the agenda in the coming weeks, but as usual, if you have any agenda items you would like to propose, please let us know. The form also includes a space to include a link to your project(s) that use technologies and standards maintained by the CG, and we would love to shine a light on these projects, including giving you the opportunity to give a short presentation on your project at our meeting.


Adrian has (very nearly) completed a first draft of migrating the existing MNX examples into JSON. You can click on any of the key names in the JSON examples to move directly to the documentation for that key. One example (organ layout) remains to be completed, and some more of the original text from the specification needs to be moved over to the new JSON version.

During this process, Adrian has collected a number of specific open questions about how the conversion from XML to JSON has affected specific elements, and he will open new GitHub discussions to prompt some discussion on those issues.

Next meeting

The next co-chairs’ meeting is scheduled for Tuesday 25 April 2023.

Community Group meeting at MOLA Conference

As a reminder to community group members, we will hold an in-person meeting on Friday 2 June 2023 as part of a new technology-focused day immediately preceding the 41st Annual MOLA Conference, to be hosted by the Berlin Philharmonic (2–5 June 2023).

The Tech Fair, to be held at the Hanns Eisler School of Music, will be an opportunity for technology-focused presentations, potentially including from organisations and companies that are members of the Community Group.

If you plan to attend the meeting but not attend the MOLA Conference itself, that will be possible (we will provide a link to register your attendance in due course), but if you are considering attending the conference, or for your company to exhibit at the Tech Fair, the registration deadline is coming very soon

Registration for the conference closes on 21 April, so there’s no time to lose: if you are planning to come to Berlin to attend the meeting in person, please register before the closing date.

If you would be interested in participating in the Tech Fair, please contact the chair of the MOLA Technology Committee, Mark Fabulich, and Amy Tackitt, MOLA’s Administrator. Mark can be reached at mfabulich at bso dot org, while Amy can be reached at amytackitt at aol dot com (please excuse the simple obfuscation of the email addresses; this is to avoid them being too easily picked up by scrapers and bots).

The W3C Music Notation Community Group meeting will take place at the conclusion of the Tech Fair schedule, at 3.30pm Berlin time (2.30pm London time, 9.30am New York Time, 6.30am Los Angeles time). We encourage as many CG members as possible to plan to attend in person, but we are also planning to provide online access to the meeting if possible.

Co-chair meeting minutes: March 14, 2023


Having decided to migrate the syntax of MNX from XML to JSON in the last co-chairs’ meeting, Adrian has added support for JSON to the docgenerator tool, which will make it possible to update the MNX specification to use JSON syntax. The next step will be to migrate the spec from JSON to XML, and Adrian anticipates that there will be some back and forth on some of the specifics of the migration of specific XML elements and attributes to JSON. Adrian anticipates creating a new discussion on GitHub with the specific examples he encounters.

Myke has started work on updating the introduction to the MNX specification in light of this change, and he anticipates being ready for a pull request in the near future.


Following some further discussion concerning the potential removal of the deprecated DTDs for MusicXML 4.1 (#481), the co-chairs have decided to postpone the removal of the DTDs in the planned MusicXML 4.1 release.

Next meeting

The next co-chairs’ meeting is scheduled for Tuesday 28 March 2023.

Co-chair meeting minutes: February 28, 2023


Following the conclusion of the consultation phase (see discussion #292), the co-chairs have decided to proceed with the transition of MNX from XML to JSON. The next steps will be to update the docgenerator tool that is used to produce the MNX specification and examples pages to be able to handle JSON, and then to update the documents themselves to show how the new MNX-based syntax will look. Adrian also plans to update the mnxconverter to produce JSON output.

Myke will look at updating the introduction page of the MNX specification to outline some of the specific advantages that using JSON will bring.


There has been some discussion concerning the use of the score-timewise element (see discussion #483) and Myke proposes that in future versions of MusicXML we should deprecate this approach, since it has never been widely used.

A reminder that there is also a proposal on the table to remove the deprecated DTDs in future versions of MusicXML. The DTDs were deprecated in MusicXML 4.0 and Myke proposes that they should be removed in the next update. If you strongly object to this, please let us know in discussion #481.

Next meeting

The next co-chairs’ meeting will be on Tuesday 14 March 2023.

Co-chair meeting minutes: February 14, 2023


Adrian has taken three existing MNX documents from our suite of examples and has reinterpreted them as JSON as an example of how MNX documents could be encoded as JSON rather than XML. He has also created a simple JSON Schema to act as a proof of concept for how this might work, and his early impressions are that JSON Schema is simple and powerful. These new examples can be found in a new GitHub discussion #292. Feedback from the community is very welcome!

The co-chairs would like to make a final decision concerning the transition to JSON at our next meeting in two weeks. We encourage the community to take a close look at these example documents and JSON Schema and provide feedback as soon as possible.

Next meeting

The next co-chairs’ meeting is scheduled for Tuesday 28 February, 2023.

Co-chair meeting minutes: February 1, 2023


The main focus for MNX development continues to be the proposal to move MNX from using XML to JSON.

Adrian is working on sample MNX documents in JSON format but doesn’t yet have anything to share; he expects to have some documents ready to share before the next co-chairs’ meeting. He is also continuing to look at the various options for JSON schemas in order to provide validation for those developers who are looking for it.

The co-chairs would also like to remind the community about issue #288, which is still under active review. This issue concerns reworking the accidental attribute for notes to remove redundancy and instead specify whether the accidental should be visible. Adrian proposes to move to a pull request for this issue, unless the community has any further feedback.

Next meeting

The next co-chairs’ meeting is scheduled for Tuesday 14 February 2023.

Co-chair meeting minutes: January 18, 2023


The co-chairs discussed at length the feedback we have received so far concerning our proposal to adopt JSON as the format for MNX documents in future. We consider the issue still open, and welcome further feedback from the community. Please catch up with the existing discussion in issue #290 and discussion #291, and add your feedback to the discussion thread rather than the issue.

As a next step, Adrian is going to prepare one or two MNX documents in JSON format so that the community can see some concrete examples of how a non-trivial MNX document will look in JSON. We are also going to investigate the different possibilities for JSON schemas, and will create a basic JSON schema to demonstrate validation for MNX documents.

Adrian has also updated the MNX specification to reflect the recent decision to encode sounding pitch rather than written pitch in MNX documents.


Myke is currently investigating the status of the domain, which has been offline for some time.

Next meeting

The next co-chair meeting is scheduled for Wednesday 1 February 2023.