MIDI-CI specification available for download

The MIDI-CI specification is now available for download by MIDI Association members. . 

MIDI Capability Inquiry

MIDI has been a successful tool for more than 3 decades. The features of MIDI 1.0 continue to work well. 

The basic semantic language of music does not change and as a result the existing definitions of MIDI as musical control messages continue to work remarkably well.

However, MIDI has not changed to fully take advantage of the new technical environment around it. We want to expand the feature set of MIDI capabilities.

At the same time, we recognize there are several key hurdles and requirements to consider as we make any additions to MIDI:

•Backwards compatibility is a key requirement. Our users expect new MIDI devices to work seamlessly with MIDI devices sold over the past 33 years.

•All MIDI Status Bytes are defined. The opcodes and data payloads are defined. It is difficult to define any new message types or change the format of the existing MIDI messages.

Expanding MIDI with new features requires a new protocol with extended MIDI messages. To protect backwards compatibility in an environment with expanded features, devices need to confirm the capabilities of other connected devices. When 2 devices are connected to each other, they use MIDI 1.0 and confirm each other's capabilities before using expanded features. If both devices share support for the same expanded MIDI features they can agree to use those expanded MIDI features. MIDI-CI provides this mechanism.

MIDI-CI: Solution for Expanding MIDI while Protecting Backwards Compatibility:

MIDI Capability Inquiry (MIDI-CI) is a mechanism to allow us to expand MIDI with new features while protecting backward compatibility with MIDI devices that do not understand these newly defined features. 

MIDI-CI separates older MIDI products from newer products with new capabilities and provides a mechanism for two MIDI devices to understand what new capabilities are supported. 

MIDI-CI assumes and requires bidirectional communication. Once a MIDI-CI connection is established between devices, query and response messages define what capabilities each device has. 

MIDI-CI then negotiates or auto-configures to use those features that are common between the devices. MIDI-CI provides test mechanisms when enabling new features. If a test fails, then devices fall back to using MIDI 1.0 for that feature. MIDI-CI improves MIDI capabilities in several key areas. 

MIDI-CI allows devices to use an expanded MIDI protocol with high resolution and multiple per note controllers. It allows for incremental adoption of new MIDI features by providing a fallback to MIDI 1.0 devices in all cases.

MIDI-CI Includes Queries for 3 major areas of expanded MIDI functionality: 

1. Protocol Negotiation

2. Profile Configuration

3. Property Exchange  

• Profile Configuration

MIDI-CI allows devices to communicate their capabilities to each other. Devices can use that capabilities information to self configure their MIDI connections and related settings. Profiles are a beneficial component in enabling intelligent auto-configuration.
A Profile is a defined set of rules for a how a MIDI Receiver device must respond to a chosen set of MIDI messages to achieve a particular purpose or to suit a particular application. In addition to defining response to MIDI messages, a Profile may optionally also define other device functionality requirements. This definition also then implies MIDI implementation of a Sender or in some cases may require a defined MIDI implementation of a Sender. 

Property Exchange 

Property Exchange, one of the features defined in MIDI-CI, is a set of mechanisms to discover, get, and set device properties using MIDI-CI Universal System Exclusive messages.

Property Exchange can allow for devices to auto map controllers, choose programs, change state and also provide visual editors to DAW's without any prior knowledge of the device or specially crafted software. This means that Devices could work on Windows, Mac, Linux, IOS and Web Browsers and may provide tighter integrations with DAW's and hardware controllers.

Property Exchange aims to provide a common way for Devices to work together by providing defined schema for describing how data is transferred.

The following list has been agreed upon as the core specifications for the new protocol.  Of course, specifications are always subject to change before final adoption. 

MIDI 2.0 prototyping session at Winter NAMM 2019 

At the prototyping session at NAMM, a number of features of MIDI 2.0 were shown.  There have been over 100,000 people who have visited the site in the past month. Numerous Youtube videos have been released and oneYoutube  has over 250,000 views with over 2000 comments. 

We have been monitoring the comments and wanted to provide some FAQs about MIDI 2.0 as well as videos of some requested MIDI 2.0 features. 

Will MIDI 2.0 devices need to use a new connector or cable?

No, MIDI 2.0 is a transport agnostic protocol.

• Transport- To transfer or convey from one place to another
• Agnostic- designed to be compatible with different devices
• Protocol-a set of conventions governing the treatment and especially the formatting of data in an electronic communications system

That's engineering speak for MIDI 2.0 is a set of messages and those messages are not tied to any particular cable or connector.

When MIDI first started it could only run over the classic 5 Pin DIN cable and the definition of that connector and how it was built was described in the MIDI 1.0 spec.

However soon the MIDI Manufacturers Association and Association of Music Electronic Industries defined how to run MIDI over many different cables and connectors.

So for many years, MIDI 1.0 has been a transport agnostic protocol.. 

MIDI 1.0 messages currently run over 5 PIN Din, serial ports, Tip Ring Sleeve 1/8" cables, Firewire and Ethernet and all the different variations of USB cables,

Can MIDI 2.0 run over those different MIDI 1.0 transports now?

No, there needs to be new specifications written for each transport. There is a new Universal Packet Format that will be common to all modern transports that will help make this work move quicker. The new Universal Packet contains both MIDI 1 .0 messages and MIDI 2.0 messages plus some messages that can be used with both.

The most popular MIDI transport today is USB. The vast majority of MIDI products are connected to computers or hosts via USB. 

USB is the first target for MIDI 2.0.

Can MIDI 2.0 provide more reliable timing?

Yes, and not only that the timing for MIDI 1.0 can also be improved. One of the new messages that can work with both MIDI 1.0 and MIDI 2.0 are Jitter Timestamps.

Goals of JR Timestamps:

• Capture a performance with accurate timing
• Transmit MIDI message with accurate timing over a system that is subject to jitter
• Does not depend on system-wide synchronization, master clock, or explicit clock synchronization between Sender and Receiver.

Note: There are two different sources of error for timing: Jitter (precision) and Latency (sync). The Jitter Reduction Timestamp mechanism only addresses the errors introduced by jitter. The problem of synchronization or time alignment across multiple devices in a system requires a measurement of latency. This is a complex problem and is not addressed by the JR Timestamping mechanism.

Can MIDI 2.0 provide more resolution?

Yes, MIDI 1.0 messages are usually 7 bit (14 bit is possible by not widely implmented because there are only 128 CC messages). In MIDI 2.0 velocity is 16 bit and the 128 control change messages, 16,384 Registered Controllers,  16,384 Assignable Controllers, Poly and channel pressure and Pitch Bend are 32 bit.

Can MIDI 2.0 make it easier to have microtonal control and different non-western scales?

Yes, MIDI 2.0 allows direct pitch control of notes ( see videos)

The really exciting part of MIDI-CI is that Protocol Negotiation paves the way for a new industry standard MIDI protocol which could enable new features like higher resolution, more channels and improved performance and expressiveness (while still maintaining backwards compatibility with current MIDI 1.0 devices). A new MIDI protocol would offer a bridge between music technology and new emerging technologies in other industries and allow creators, performers, and consumers to enjoy new and exciting musical experiences in the future.

by Yutaka Hasegawa, chairman of AMEI