MIDI 1 (Musical Instrument Digital Interface)
MIDI is a technical standard that describes a standard means of, communications, digital interface, and electrical connectors that connect a wide variety of electronic musical instruments, computers, and related audio devices for playing, editing, and recording music.
MIDI Channels
This is a subject that seems (for some people) to cause confusion.
A MIDI channel allows a specific device to receive its own set of MIDI data. So any MIDI Data sent on say channel 1 will only be received by a connected device such as a MIDI Synthesizer which is set to use Midi Ch1.
When a MIDI device is set to “All” then it will receive data from all the other interconnected devices.
This allows us to control separate devices from separate sources. So in your DAW you could have three different keyboards controlling three different VST synthesizers, and a control surface set up as channels 1,2,3 for the individual Synthesizers, and channel four as the control channel for a mixer.
A single MIDI cable can carry up to sixteen channels of MIDI data, each of which can be routed to a separate device. Each interaction with a key, button, knob or slider is converted into a MIDI event, which specifies musical instructions, such as a note’s pitch, timing and loudness. One common MIDI application is to play a MIDI keyboard or other controller and use it to trigger a digital sound module (which contains synthesized musical sounds) to generate sounds, which the audience hears produced by a keyboard amplifier. MIDI data can be transferred via MIDI or USB cable, or recorded to a sequencer or digital audio workstation to be edited or played back.
Many groups, (Tangerine Dream for one) and studios have embraced this technology, as it’s much easier to transport, nowhere near as heavy, and unlike analogue synthesizers always stays in tune, and is a lot cheaper than a stack of of hardware synthesizers. Which is easier to transport, maintain and set up; three laptops and sound interfaces feeding into a mixer, or three Moog Modulars?
Preserving a performance.
A file format that stores and exchanges the data is also defined.
The advantages of MIDI include small file size, ease of modification (there are many software MIDI editors) along with a wide choice of electronic instruments, synthesizers, software synthesizers, or digitally sampled sounds.
A MIDI recording of a performance on a keyboard could sound like a piano or other keyboard instrument; however, since MIDI records the messages and information about their notes and not the specific sounds, this recording could be changed to many other sounds, ranging from synthesized or sampled guitar or flute to full orchestra.
Ease of communication.
Before the development of MIDI, electronic musical instruments from different manufacturers could generally not communicate with each other. This meant that a musician could not, for example, plug a Roland keyboard into a Yamaha synthesizer module. With MIDI, any MIDI-compatible keyboard (or other controller device) can be connected to any other MIDI-compatible sequencer, sound module, drum machine, synthesizer, or computer, even if they are made by different manufacturers.
MIDI 2.0
SynthEdit MIDI pins can handle both MIDI 1.0 and MIDI 2.0 standards.
From Version 1.5 many SynthEdit modules accept either MIDI 1 or MIDI 2 but send MIDI 2.
About MIDI 2.
Back in 1983, musical instrument companies that were in fierce competition nonetheless banded together to create a specification to allow musical instruments to communicate with each other, and with computers. This was MIDI 1.0, the first universal Musical Instrument Digital Interface.
Nearly four decades on, we can see that MIDI was crafted so well that it has remained useful and relevant. Its ability to join computers and musical instruments has become an major part of live performances for recording, controlling mixers, programming Synthesizers, and even stage lighting.
Now, MIDI 2.0 is taking the technology even further, deliberately retaining backward compatibility with MIDI 1.0 equipment and software already in use.
Here’s why MIDI 2.0 is the biggest advance in music technology in decades:
MIDI 2.0 Means Two-way MIDI Conversations
MIDI 1.0 messages were unidirectional: from the transmitter to a receiver. MIDI 2.0 is bi-directional and changes MIDI from a monologue to a dialogue between computers and instruments.
For example, with the new MIDI-CI (Capability Inquiry) messages, MIDI 2.0 devices can talk to each other, and auto-configure themselves to work together. They can also exchange information on functionality, which is key to backward compatibility.
MIDI 2.0 software and equipment can “talk” to a device, and if it doesn’t support MIDI 2.0, and then it can simply switch to the old MIDI 1.0 protocol.
Higher Resolution, More Controllers and Better Timing
To deliver an even higher level of musical and artistic expressiveness, MIDI 2.0 re-imagines the role of performance controllers, which is the aspect of MIDI that converts human performance gestures to control signals computers can understand.
Controllers have become easier to use, and there are more of them: over 32,000 controllers, including controls for individual notes.
Enhanced, 32-bit resolution gives controls a smoother, continuous, “analogue” feel. Note-On options were added for articulation control and setting precise note pitch.
In addition to this, dynamic response (velocity) has been improved.
What’s more, major timing improvements in MIDI 2.0 can also apply to MIDI 1.0 devices in fact, some MIDI 1.0 gear can actually “retrofit” certain MIDI 2.0 features.
Profile Configuration
MIDI gear can now have Profiles that can dynamically configure a device for a particular user scenario.
If a control surface queries a device with a “mixer” Profile, then the controls will map to faders, pan-pots, and other mixer parameters.
But when connected with a “drawbar organ” Profile, that same control surface can map its controls to virtual drawbars and other keyboard parameters, or map to dimmers if the profile is a lighting controller. This saves enormously on setup time, improves workflow, and eliminates time consuming manual programming.
Property Exchange
Profiles set up an entire device, and Property Exchange messages provide specific, detailed information sharing.
These messages can discover, retrieve, and set many properties like preset names, individual parameter settings, and unique functionalities.
Essentially, everything one MIDI 2.0 device needs to know about the MIDI 2.0 device it’s connected to.
For example, your DAW or recording software could display everything you need to know about a synthesizer on-screen, effectively bringing hardware synthesizers up to the same level of programmability as their software counterparts.
Built for the Future.
Unlike MIDI 1.0, which was initially tied to a specific hardware implementation, the new Universal MIDI Packet format makes it easy to implement MIDI 2.0 on any digital transport (like USB or Ethernet). To enable future applications that we haven’t yet developed, there’s ample space still in the standard reserved for brand-new MIDI specifications and messages.
For more detailed information on (and it’s very detailed and complex) on MIDI 2 standards and protocols visit the MIDI organisation’s website
https://www.midi.org/midi-articles/details-about-midi-2-0-midi-ci-profiles-and-property-exchange
Converting MIDI 1 to MIDI 2
SynthEdit provides a MIDI converter module that can convert MIDI 1 to MIDI 2 and vice versa.
This is useful for maintaining compatibility with MIDI 1 only modules.
MIDI 2.0 is now the default MIDI standard, because MIDI 1, MIDI MPE, and Steinberg Note-Expression can all be converted losslessly to MIDI 2. However it’s not always possible to convert MIDI 2 to MIDI 1.
The SynthEdit SDK now provides helper classes that will convert MIDI for you.
This allows you to write your MIDI code without having to handle all the different types of MIDI.
Note: It’s recommend that you write your modules to use MIDI 2.
The SDK contains the ‘MIDI to Gate’ module that shows how to write a MIDI 2 module that also accepts MIDI 1 transparently.
You can intercept the MIDI signals anytime before it reaches the Patch Automator.
Note that the MIDI-CV also secretly sends it’s MIDI data there too.
By default the MIDI in SE 1.5 is Version 2.0. The MIDI-In module converts everything to MIDI V 2.0. You can send version 1.0 also, but SE’s own MIDI modules will tend to covert it back into Version 2.0 if they get a chance .
MIDI Messages and (basic) Standards.
MIDI messages are made up of 8-bit bytes that are transmitted serially at a rate of 31.25 Kbit/s. This rate was chosen because it is an exact division of 1 MHz, the operational speed of many early microprocessors. The first bit of each word identifies whether the byte is a status byte or a data byte, and is followed by seven bits of information. A start bit and a stop bit are added to each byte for framing purposes, so a MIDI byte requires ten bits for transmission
A MIDI link can carry sixteen independent channels of information. The channels are numbered 1–16. A device can be configured to only listen to specific channels and to ignore the messages sent on other channels (omni off mode), or it can listen to all channels, effectively ignoring the channel address (omni on). An individual device may be monophonic (the start of a new note-on MIDI command implies the termination of the previous note), or polyphonic (multiple notes may be sounding at once, until the polyphony limit of the instrument is reached, or the notes reach the end of their decay envelope, or explicit note-off MIDI commands are received). Receiving devices can typically be set to all four combinations of omni off/on and mono/poly modes
A MIDI message is an instruction that controls some aspect of the receiving device. A MIDI message consists of a status byte, which indicates the type of the message, followed by up to two data bytes that contain the parameters. MIDI messages can be channel messages sent on only one of the 16 channels and monitored only by devices on that channel, or system messages that all devices receive. Each receiving device ignores data not relevant to its function. There are five types of message: Channel Voice, Channel Mode, System Common, System Real-Time, and System Exclusive.
Channel Voice messages transmit real-time performance data over a single channel. Examples include “note-on” messages which contain a MIDI note number that specifies the note’s pitch, a velocity value that indicates how forcefully the note was played, and the channel number; “note-off” messages that end a note; program change messages that change a device’s patch; and control changes that allow adjustment of an instrument’s parameters. MIDI notes are numbered from 0 to 127 assigned to C−1 to G9. This corresponds to a range of 8.175799 to 12543.85 Hz (assuming equal temperament and 440 Hz A4) and extends beyond the 88 note piano range from A0 to C8.
System Exclusive messages
System Exclusive (SysEx) messages are a major reason for the flexibility and longevity of the MIDI standard. Manufacturers use them to create proprietary messages that control their equipment more thoroughly than standard MIDI messages could. SysEx messages use the MIDI protocol to send information about the synthesizer’s parameters, rather than performance data such as which notes are being played and how loud. SysEx messages are addressed to a specific device in a system. Each manufacturer has a unique identifier that is included in its SysEx messages, which helps ensure that only the targeted device responds to the message, and that all others ignore it. Many instruments also include a SysEx ID setting, so a controller can address two devices of the same model independently. SysEx messages can include functionality beyond what the MIDI standard provides.
Time code
A sequencer can drive a MIDI system with its internal clock, but when a system contains multiple sequencers, they must synchronize to a common clock. MIDI Time Code (MTC), developed by Digidesign, implements SysEx messages that have been developed specifically for timing purposes, and is able to translate to and from the SMPTE time code standard. MIDI Clock is based on tempo, but SMPTE time code is based on frames per second, and is independent of tempo. MTC, like SMPTE code, includes position information, and can adjust itself if a timing pulse is lost. MIDI interfaces such as Mark of the Unicorn’s MIDI Timepiece can convert SMPTE code to MTC
More Info: https://en.wikipedia.org/wiki/MIDI
