MIDI USB is a common way to connect musical instruments, controllers, and computers using the standard Universal Serial Bus (USB) cable and ports. It allows devices to send and receive Musical Instrument Digital Interface (MIDI) data digitally over a USB connection, combining the capabilities of the MIDI protocol with the convenience and speed of USB technology.
Understanding the Basics
To grasp MIDI USB, it's helpful to understand the two core components: MIDI and USB.
What is MIDI?
As the name suggests, MIDI USB relies on the Musical Instrument Digital Interface (MIDI) standard. MIDI is not audio; it's a set of instructions or commands that describe musical events, such as:
- Note on/off (which key is pressed/released)
- Velocity (how hard the key is pressed)
- Pitch bend
- Control changes (like moving a fader or knob)
- Timing information
According to the reference, Musical Instrument Digital Interface (MIDI) is a standard protocol for interconnecting computers with musical instruments, stage lighting, and other time-oriented media. This protocol allows different electronic music devices to communicate with each other, regardless of the manufacturer.
What is USB?
USB stands for Universal Serial Bus. It's a standard type of connection used for a wide range of electronic devices (computers, phones, peripherals) to connect, communicate, and often supply electric power. USB ports and cables are ubiquitous on modern computers and devices.
How MIDI Works Over USB
Prior to USB, MIDI devices typically used dedicated MIDI cables with 5-pin DIN connectors. MIDI over USB replaces these cables with a single USB connection.
When you connect a MIDI device (like a keyboard) to a computer using a USB cable:
- The device sends MIDI data (e.g., "Note C4 On with Velocity 100") digitally.
- This data is encapsulated and transmitted over the USB connection.
- The computer receives the data via its USB port and routing software (like a Digital Audio Workstation - DAW) directs it to a virtual instrument or other destination.
Key Benefits of MIDI USB
- Simplicity: Often requires just one cable for both data and power (no separate power adapter needed for many devices).
- Ubiquity: USB ports are standard on nearly all modern computers.
- Speed: USB provides faster data transfer than traditional MIDI cables.
- Multi-channel: A single USB connection can handle multiple virtual MIDI ports, allowing more complex setups.
- Driver-less (often): Many MIDI USB devices are "class-compliant," meaning they work without needing custom drivers on popular operating systems (Windows, macOS, Linux, iOS, Android).
Key Features and Modern Support
MIDI USB has evolved over the years, benefiting from advancements in both the MIDI protocol and USB standards.
MIDI 2.0 and USB
The original MIDI protocol (often referred to now as MIDI 1.0) has been around since the early 1980s. A significant update, MIDI 2.0, was introduced to add features like higher resolution, property exchange (devices describing their capabilities), and bi-directional communication.
The reference specifically mentions: Starting in Android 13, MIDI 2.0 support is added to the USB transport. This highlights that USB is a modern and capable transport layer for the latest version of the MIDI protocol on various platforms, including mobile ones like Android.
Devices Using MIDI USB
MIDI USB is the standard connection method for a vast range of music technology hardware today. Examples include:
- MIDI Keyboards and Controllers: Devices without their own sounds that control software instruments or external hardware.
- Synthesizers and Digital Pianos: Instruments with built-in sounds that can also send/receive MIDI data.
- Drum Machines and Pad Controllers: Used for programming beats and triggering samples.
- Audio Interfaces: Many interfaces include MIDI I/O, often connecting to the computer via USB.
- Stage Lighting Controllers: USB is used to send MIDI commands to control DMX lighting systems.
Why MIDI USB is Popular
MIDI USB simplifies connectivity for musicians and producers. Instead of needing dedicated MIDI interfaces and multiple cables, a single USB connection handles data flow, often providing power as well. This plug-and-play convenience has made it the dominant way to connect MIDI hardware to computers and compatible mobile devices.
| Feature | Traditional MIDI (5-pin DIN) | MIDI Over USB |
|---|---|---|
| Cable Count | Multiple (In, Out, Thru) | Usually one |
| Power | Requires separate adapter | Often bus-powered |
| Speed | Fixed, slower (31.25 kbaud) | Faster (USB standard speed) |
| Complexity | Requires MIDI Interface | Often direct connection |
| Modern Support | Less common on new devices | Standard connection today |
MIDI USB effectively merges the versatile communication language of MIDI with the efficient and widely available hardware connection of USB, creating an industry-standard solution for digital music creation and performance.
