What is a MIDI enabled device?

MIDI stands for Musical Instrument Digital Interface. It is a technical standard that describes a protocol, digital interface and connectors that allows a wide variety of electronic musical instruments, computers and other related devices to connect and communicate with one another.

The main purpose of MIDI is to allow different musical instruments, like synthesizers, samplers, drum machines, sequencers and computers, to communicate and synchronize with each other. This allows MIDI devices to control one another, so that one device can trigger sounds and playback in another device. The MIDI protocol transmits event messages that specify notation, pitch, velocity, vibrato, panning and clock signals. This data can be used to trigger sounds, sequence music and control parameters in MIDI enabled devices.

The key benefits of the MIDI standard are:

Allows connectivity and communication between electronic music devices from different manufacturers.
Standardizes the way music data and timecode is transmitted between devices.
Enables complex control of parameters in MIDI compatible equipment using MIDI control messages.

Allows MIDI data to be recorded, edited and played back using standalone hardware sequencers or computer software.

By providing a universal protocol for electronic musical instruments, the advent of MIDI in 1983 played a pivotal role in the development of computer music production and digital audio workstations.

Brief History of MIDI

The origins of MIDI date back to the early 1980s. At that time, digital synthesizers from different manufacturers were unable to communicate with each other. This made it difficult for musicians using equipment from different brands to synchronize their instruments.

The initial concept for MIDI was developed by Dave Smith, founder of Sequential Circuits, and Ikutaro Kakehashi, founder of Roland Corporation. In 1981, they introduced MIDI 1.0 at the NAMM trade show. This allowed different digital musical instruments and devices to connect with each other and exchange musical data.

Since its inception, MIDI has undergone revisions and enhancements. MIDI 1.0 was the original adopted standard. Later versions like General MIDI aimed to improve quality and expand features. The most recent version, MIDI 2.0, was released in 2020 with increased resolution, more channels, and better integration of computer-based systems.

Over the past 40 years, MIDI has become an indispensable part of music creation. It is a technical standard that allows seamless communication between electronic instruments, computers, smartphones and other hardware. MIDI enabled musicians to build more complex systems for music production.

How MIDI Devices Work

MIDI devices communicate with each other by sending MIDI messages and data. There are two main types of MIDI messages:

Channel messages: These include notes, controller data, pitch bend, aftertouch, etc. Channel messages are sent on one of 16 MIDI channels.
System messages: These include timing data, song position, start/stop commands, etc. System messages are not assigned to any specific MIDI channel.

The most common MIDI data types are:

Note On – triggered when a note is played.
Note Off – triggered when a note is released.

Controller Change – changes parameters like volume, pan, sustain, etc.
Program Change – changes instrument or patch.
Pitch Bend- controls pitchsweep.

MIDI cables have 5-pin DIN connectors that carry the MIDI data. Standard MIDI cables are unidirectional and can only transmit in one direction. However, MIDI throughput ports allow data to be forwarded in both directions.

When you press a key on a MIDI controller, it sends MIDI data to the sound source indicating which note was played, its velocity, and how long it was held. The sound source receives this MIDI data and plays the corresponding sound. MIDI data can also be recorded into and played back from a DAW.

To connect MIDI devices, the MIDI out of the controller is connected to the MIDI in of the sound source using a standard 5-pin MIDI cable. Most MIDI interfaces have both MIDI in and out ports to allow chaining multiple devices.

Types of MIDI Devices

There are several common types of devices that support MIDI connectivity and communication:

MIDI controllers allow musicians to play and manipulate software instruments and DAWs using physical controls. Common MIDI controllers include keyboards, drum pads, and control surfaces with knobs, faders, and buttons. They send MIDI performance data but do not generate sound themselves.

Sound modules and synthesizers are the devices that actually produce audio from MIDI data. They contain embedded sounds and instrument presets. When they receive MIDI note messages, they know which instrument to play and at what parameters. Examples include rackmount sound modules and keyboard synthesizers like the Yamaha DX7.

MIDI interfaces provide the ports and connectivity to get MIDI data in and out of computers and mobile devices. They enable MIDI instruments and controllers to communicate with audio production software. Common interfaces include USB-MIDI cables and audio interfaces with onboard MIDI I/O.

Finally, digital audio workstations (DAWs) and sequencers use MIDI sequencing to record, edit, and play back MIDI performances. In a DAW like Ableton Live or Logic Pro, MIDI clips can be manipulated like audio clips. The MIDI data is sent from the DAW to instrument plugins or external sound modules. Examples include Ableton Live, Logic Pro, and Pro Tools.

Connecting MIDI Devices

MIDI devices need to be connected together using special cables and connectors in order to communicate. The most common type of cable used is a 5-pin DIN cable. MIDI devices have MIDI input and output ports that cables plug into. By connecting the output of one device to the input of another, MIDI data can be transferred between them.

MIDI devices can be daisy chained together, allowing multiple devices to communicate on one channel. This is done by connecting the MIDI out of one device to the MIDI in of the next, and so on in a chain. The MIDI data flows from one device to the next down the chain.

In recent years, wireless MIDI connectivity has also become an option. Wireless MIDI adapters can be used to transmit MIDI data wirelessly between devices, eliminating the need for cables. Popular wireless MIDI protocols include Bluetooth MIDI and Apple’s AirPlay. Wireless MIDI allows greater flexibility and range of motion when using MIDI controllers and instruments.

Overall, the standard 5-pin MIDI cable is still the most common method used to connect MIDI devices today. However, wireless MIDI technology continues to improve and become more affordable [1], allowing for cable-free MIDI setups, which may become more prevalent in the future.

MIDI Data and Messages

MIDI messages allow various devices to communicate with each other. There are two main types of MIDI messages:

Channel Messages: These messages occur on 16 different channels and convey musical performance data like notes, controllers, program changes, etc. Common channel messages include:

Note On – Triggers a note to start playing at a certain velocity

Note Off – Triggers a note to stop playing
Program Change – Changes the sound/patch on a device
Control Change (CC) – Adjusts parameters like volume, panning, effects

System Messages: These messages occur on a system channel and handle overall MIDI functions like timing and synchronization. Some examples are:

System Exclusive – Sends proprietary data to a specific device
Song Select – Chooses a sequence or song on a device

Song Position Pointer – Provides timeline information for synchronization

The MIDI data bandwidth is 31.25 kbps. This allows for rapid transmission of performance data like note on/off messages, program changes, and controller adjustments (Source). However, MIDI has limitations when working with complex production techniques or high quality audio playback.

Using MIDI in Music Production

MIDI is an integral part of music production, both for professional and hobbyist musicians. Here are some of the main ways MIDI is used in the studio:

Recording and editing MIDI data – One of the biggest advantages of MIDI is that performance data (notes, velocities, control changes etc.) can be easily recorded, edited and manipulated. This allows producers to capture musical ideas quickly and edit performances to perfection.

Using virtual instruments – MIDI data is commonly used to trigger virtual software instruments to generate sounds. This saves money compared to hiring live instrumentalists, and allows endless sound possibilities.

MIDI synchronization and tempo – MIDI clock and timecode signals allow instruments, sequencers and devices to stay in sync. The tempo map from a MIDI sequencer can control the timing of other gear.

MIDI show control – Special MIDI messages can be used to automate and synchronize lighting, video and stage effects during live performances. This is known as MIDI show control.

By harnessing the power and flexibility of MIDI data, computer-based studios can achieve results that were once only possible with roomfuls of traditional equipment and musicians. As this article explores, MIDI is an essential “digital glue” for the modern music workflow.

Advantages of MIDI

MIDI offers several important advantages that have made it an essential technology for music production:

Small data size – Unlike audio files, MIDI files don’t contain the actual sound recordings, just the instructions for creating the music. This means MIDI files are extremely small, often less than 10 KB even for minutes of music.

Flexibility and expandability – MIDI data is like a set of instructions that can be manipulated and modified in endless ways. You can change the key, tempo, velocity, articulation, instrumentation, and many other aspects after recording.

Manufacturer interoperability – Unlike some other music technologies, MIDI was designed from the outset to enable different electronic instruments by different manufacturers to communicate. This interoperability unleashed an explosion in the use of synthesizers, samplers, drum machines and more from different makers.

Enables hardware/software integration – MIDI provides seamless interaction between hardware like keyboards and drum machines and software like digital audio workstations and virtual instruments. This bridging of the hardware-software divide opened up creative possibilities.

Disadvantages of MIDI

While MIDI has revolutionized music production and enabled a high degree of connectivity between electronic instruments, it does have some limitations:

MIDI has a relatively limited data bandwidth. The standard MIDI protocol only allows for a data transfer rate of 31.25 kB/s. This limits the amount of controller data and musical nuance that can be transmitted between devices (1).

The MIDI protocol can also introduce latency issues, especially when using multiple devices connected in a chain. The time it takes for MIDI messages to be transmitted and recognized can result in lags between when a note is played and when the sound is heard (2).

There are also some polyphony limitations with MIDI. While MIDI channels allow for 16 simultaneous voices, some early hardware synths were limited to 12 or 24 note polyphony. Newer instruments have expanded polyphony, but MIDI itself has no built-in way to handle extremely dense polyphonic playback.

Finally, MIDI does not transmit audio signals. It only sends control messages to trigger sounds on a receiving instrument. To capture audio output requires separate audio cables between devices or recording the audio output separately in a DAW.

(1) https://gearspace.com/board/geekzone/999955-main-limitations-problems-midi-possible-new-solutions.html

(2) https://eimearclarke.wordpress.com/2015/03/13/limitations-of-midi-technology/

The Future of MIDI

MIDI technology continues to evolve to meet the needs of modern music production. Some key developments on the horizon include:

MIDI 2.0 specifications – In January 2020, the MIDI Manufacturers Association announced the release of the MIDI 2.0 specification, the first major update to MIDI since its inception in 1983. MIDI 2.0 increases the resolution and adds new features like increased precision, extended resolution, increased expressiveness, and tighter timing. This allows for a more nuanced and realistic performance playback (Source).

MIDI over USB and Ethernet – Currently, MIDI data is transmitted over 5-pin DIN cables. However, as computers and mobile devices become more integrated into music production, there is a push to transmit MIDI data over USB and Ethernet cables for simplified connectivity.

Integration with computers and mobile devices – The widespread adoption of smartphones, tablets, and laptops is driving increased integration between MIDI instruments/controllers and mobile/computer platforms. This allows for more portable and flexible music production and performance setups.

New MIDI controller designs – MIDI controller manufacturers continue to innovate with new form factors, connectivity options, expressive capabilities, and tighter integration with computers and mobiles devices. Some examples include touchscreen controllers, belt-worn controllers, and motion sensor-equipped controllers (Source).

As MIDI technology evolves, the possibilities for creative music production and performance continue to expand. The future points towards increased realism, expression, and seamless integration between traditional MIDI instruments and the modern computer-centric studio and stage.