What Is MIDI and What Is It Used For?
- Noise Harmony
- Apr 5
- 6 min read
Updated: Apr 8
MIDI — short for Musical Instrument Digital Interface — is one of the most important technologies in music production. But here’s the catch: MIDI doesn’t create sound. Instead, it sends digital instructions that tell instruments and software what to play and how to play it. It’s basically the language that allows electronic instruments, synthesizers, DAWs, and other gear to send information and talk to each other.
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A Short History of MIDI
Before MIDI came along, synthesizers and drum machines from different brands couldn’t communicate. Each one used its own proprietary system. In the early 1980s, Roland founder Ikutaro Kakehashi and Dave Smith from Sequential Circuits proposed a standard that would let gear from different manufacturers work together. MIDI 1.0 was born.
The first public demo happened at NAMM 1983, connecting a Prophet-600 to a Roland Jupiter-6. That simple handshake became the foundation of how we produce, perform, and even teach music today.
How MIDI Works
MIDI transmits digital messages that describe musical events. For example:
A note is played (Note On)
A note is released (Note Off)
How hard it’s played (Velocity)
Pitch bend and modulation
Sustain pedal activation
Instrument or patch changes (Program Change)
And many others…
Originally, these messages were sent using 5-pin DIN cables and could carry up to 16 channels of data simultaneously. These days, MIDI is also sent via USB, Bluetooth, and even over network protocols.
In practical terms, this means a single MIDI keyboard can control multiple virtual instruments in your DAW, or send commands to a hardware synth and a drum machine at the same time.
MIDI Files and Formats
A MIDI file (.mid) stores a sequence of MIDI instructions. These files are extremely lightweight because they don’t include audio — only performance data like notes, tempo, and controller changes.
For example, a MIDI file of a piano part could be played by a grand piano plugin, a synth lead, or even a distorted guitar patch. You can change the instrument, tempo, and key — all without needing to re-record anything.
MIDI files come in different types:
Type 0: All data is stored on a single track.
Type 1: Data is split into multiple tracks (more common for multichannel music).
Type 2: Rare, often used in pattern-based sequencing.
MIDI Messages Explained
MIDI messages are made of binary data and typically include a status byte (which tells the system what kind of message it is) and one or two data bytes (which carry things like note number or velocity).
Here are a few examples:
Note On: 0x90 (channel 1), followed by note number (0x3C = Middle C), then velocity (0x7F)
Note Off: 0x80 + note number + velocity
Control Change: used for knobs, faders, pedals, etc.
Program Change: selects different presets or instruments
There’s also System Exclusive (SysEx) messages. These are custom messages used by specific manufacturers to do things like send patch data, update firmware, or control unique hardware functions. They aren’t standardized but are powerful for advanced users.
MIDI vs Audio
This is a common point of confusion. MIDI is not audio. A WAV or MP3 file contains recorded sound. A MIDI file contains instructions.
This gives you a lot of freedom. You can:
Change instruments or sounds on the fly
Transpose parts instantly
Quantize or fix mistakes without re-recording
Automate dynamics, filters, or expression
It’s one of the reasons MIDI is essential in electronic music, film scoring, game audio, and live performance.
MIDI and Synchronization
MIDI can also sync devices. There are two main methods:
MIDI Clock: Syncs tempo between devices (drum machines, sequencers, etc.)
MIDI Timecode (MTC): Used more in film and TV to sync MIDI with video or audio systems.
This allows multiple hardware units, DAWs, or lighting systems to stay in perfect time — even across complex setups.
MIDI Controllers and Uses
There are many kinds of MIDI controllers. Some look like keyboards, others like drum pads, faders, guitars, or even wind instruments.
You can use them to:
Play virtual instruments (U-he Diva, Xfer Serum, etc.)
Control plugins and synths
Map knobs and faders to filters, EQs, effects
Trigger loops or scenes in live performance
Switch presets on hardware (Line 6, Korg, etc.)
With software like Ableton Live, Logic Pro, FL Studio, or Reaper, MIDI is at the core of sequencing, automation, sound design, and mixing.
MIDI in Sound Design and Presets
If you use preset packs — like the ones we create at Noise Harmony — MIDI helps bring them to life. Whether you’re using synths like U-He Diva, Ableton Wavetable, or guitar processors like Line 6 Helix, MIDI is the link between your controller and the sound engine.
Want to automate a filter sweep? MIDI can do it.
Want to switch between clean and ambient reverb presets on a Helix during a set? MIDI handles that, too.
Check out our custom-made presets for U-He Diva!
NH STH Delayed Prophecy_E
NH RTH Oliver with Twist_Fm
MPE: MIDI Polyphonic Expression
MPE, short for MIDI Polyphonic Expression is a newer way for instruments and controllers to communicate, allowing each note you play to have its own expression. Unlike standard MIDI, where all notes on a channel share the same pitch bend, modulation, and pressure data, MPE gives every note its own lane. That means you can bend one note, slide another, and add pressure to a third, all at the same time, without them interfering with each other.
Imagine playing a chord and being able to wiggle one finger to add vibrato to just that note, or slide another note up while the rest stay put. It's the kind of nuance you’d expect from an acoustic instrument – but now it's possible with digital gear.
MPE delivers an amazing experience when paired with modern expressive controllers like the ROLI Seaboard, LinnStrument, or Expressive E Osmose. These devices go beyond standard keyboards, picking up on subtle gestures like finger slides, pressure, and lifts to shape your sound in real time.
The spec was officially adopted by the MIDI Manufacturers Association in 2018, and support for MPE has been growing fast across both hardware and software.
MPE actually helped inspire MIDI 2.0, which pushes expressive control even further.
MIDI 2.0: The Next Chapter
In 2020, MIDI 2.0 officially arrived, bringing the first major update to the MIDI standard since it was introduced back in the early ‘80s. MIDI 1.0 changed everything — it gave electronic instruments a way to talk to each other. But the world of music production has come a long way since then, and it was time for MIDI to catch up.
MIDI 2.0 takes everything that made the original great and upgrades it for modern workflows. It’s faster, smarter, and way more expressive — designed with today’s producers, performers, and developers in mind.
So, what changed with MIDI 2.0?
High-resolution control - With MIDI 1.0, everything from velocity to pitch bend was limited to just 128 steps (7-bit resolution). MIDI 2.0 blows that wide open with 32-bit resolution, giving you ultra-smooth transitions and super-detailed expression — the kind of response that feels more like a real instrument than a grid of data.
Two-way communication - Devices can now talk back to each other. A controller can ask a synth what it can do, and adjust its controls automatically. No more trial and error. It’s like MIDI finally got smart.
Automatic setup - MIDI 2.0 devices can identify themselves and configure things automatically, which means way less time spent mapping controls and way more time making music.
Better articulation - New message types let you convey musical expression more accurately, like legato, staccato, and dynamics — especially useful for realistic virtual instruments and orchestral plugins.
Why MIDI Still Matters
After more than 40 years, MIDI is still the standard in how we make and perform music. What started as a simple way to connect gear has grown into a complex system. Thanks to modern features like MPE and MIDI 2.0, we have tools that let us play and shape sound with a level of expression and control that feels almost human.
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