The HDWG has been developing messages for device configuration,
to enable saving and restoring of a complete state of an HD network
(e.g. an entity can be queried for individual settings and/or a dump
of that entity’s current configuration.)
The WG produced a new draft in 2013 which simplifyies the
protocol by reducing the number of messages, and also improves
synchronization. Both real time and beat-based time stamps have been
proposed, and multiple messages can share a common time stamp.
Variable length messages allows the HD protocol to contain fewer
overall number of messages, without sacrificing any features. Since
a goal of HD is to be "transport agnostic," the HDWG has
been studying HD over USB as well as HD over Ethernet. Additional
query and response messages will make it possible to do conformance
testing. In the coming year, the WG plans to begin studying
potential recommended practices for different products and
On January 27, members of the HD Protocol Working Group
provided a private demonstration of prototype engineering hardware and software
using a working draft of the HD Protocol Specification. Various
devices were connected via wired and wireless Ethernet, to
demonstrate the plug-and-play connection and session management
capabilities built into the HD Protocol, as well as features such as
higher resolution controls, more throughput, and MIDI device
compatibility. The purpose of the demonstration was to encourage more companies
to participate in completing the HD Protocol Specification.
Therefore, invitations to the event were extended only to
companies that qualify to be MMA members and express an interest in
joining MMA to participate in this project.
In response to MMA member comments at the 2011 MMA AGM, the HD
Protocol working Group in 2011 produced two new revisions to the
draft HD Protocol Specification. The last draft was approved by the
MMA Technical Standards Board (TSB) for implementation testing to
validate and evaluate the specification (which is still considered
to be under development). Eleven companies attended a
"plug-fest" on the Monday after the NAMM Show to share
implementation experiences, identify areas of the specification that
need work, and test the interoperability of four
independently-developed code-bases. The results will be discussed in
the MMA, along with next steps and the future work-plan.
MMA members reviewed a rough draft of an HD Protocol and UDP Transport proposal during the Annual General Meeting in January during
NAMM. The proposal establishes the features that are proposed for HD
protocol, but lacks the clarity and completeness needed for a
published proposal, and has yet to be tested nor decided by a vote
of the MMA membership.
Among the new features proposed for HD Protocol is a more
advanced palette of note messages. In addition to the default
interpretation of the note number field as a pitch (as you might do
with MIDI 1.0, excepting percussion staves), the draft proposal
allows HD senders to specify a direct pitch. When a Note message
specifies Direct Pitch, rather than the Note Number field
determining the pitch of the note, the specified Direct Pitch value
is used (as closely as possible). The Direct Pitch field sets the
base pitch of the note, overriding the base pitch that would
otherwise be selected by the note number, allowing easy
implementation of alternate tuning systems.
In addition to Note On and Note Off, the draft includes a Note
Update message that allows modification of parameters or controllers
during the lifetime of a note. Note Update messages with Direct
Pitch are not the same as Pitch Bend, since these Note Update
messages will update the base pitch. The Pitch Bend controller
provides an offset to this base pitch.
More information about proposed features may
be provided in the future, however interested parties are
encouraged to join MMA to participate in development of the
For the third year in a row, dozens of MIDI hardware and software manufacturers
gathered at the Marriott in Anaheim CA, in conjunction with the Winter NAMM Show,
to discuss ideas for a new High Definition protocol for musical instruments.
"MIDI has worked fantastically for more than 25 years," said MMA President and CEO Tom White. "High
Definition protocol could encourage
market growth through more expressive products, improved ease of use, and new and innovative
applications. Plus new High Definition devices and software would be designed to be compatible with all
of the great MIDI hardware and software now and for the future."
The proposed changes would increase the number of MIDI Channels and Controllers, and
provide greater resolution in data values for all of the current MIDI 1.0 messages.
Moreover, all of this would be accomplished with single messages, as opposed to the compound
messages often used in MIDI 1.0, which means using and editing MIDI data will be far easier
for both developers and users. The new protocol could also support the creation of entirely
new messages that were not practical with the MIDI 1.0 protocol.
"At this point our 'HD Protocol' is still under development, but we've seen a lot of
interest from both hardware and software developers," said White. "Our policy is not to
discuss MMA Specifications publicly until they're officially adopted, but in this case
we want to make sure that all qualified companies know what we are thinking about so they
have the opportunity to participate before the first version is published."
The original MIDI 1.0 Specification, developed in 1983, has been the foundation for
interoperability of digital musical instruments for 25 years. The initial "MIDI 1.0
Specification" contained the rules for remote control of keyboard devices, but over
the years additional specifications were developed for file exchange, sound exchange,
synthesizer design, and new applications such as stage lighting and ring-tones. Today the
term "MIDI" applies to the wide variety of file formats, applications, and device
specifications defined by the MIDI Manufacturers Association.
The MIDI Manufacturers Association is an industry non-profit organization that is
responsible for maintaining and extending MIDI. Formed in 1985 by the original developers
of the MIDI 1.0 Specification, the MMA provides a forum where companies using MIDI can
cooperate and collaborate to make their equipment interoperable.
Companies that are interested in participating in the development of the new HD Protocol
should contact the MMA (see the contact form on this