Windows 11 preview adds MIDI 2.0 support after decades-long wait

Microsoft updates the MIDI stack

Microsoft released the MIDI 2.0 ecosystem to Windows Insiders in the Canary Channel on February 5, 2025. This update delivers a long-awaited overhaul of the Windows MIDI subsystem, which has remained largely unchanged for decades. Principal software engineer Pete Brown and Gary Daniels announced the preview after more than a year of internal development and testing.

The new implementation introduces a core Windows MIDI Services architecture. This service manages all MIDI traffic on the system, moving away from the older driver-only model. It provides a modern API that developers can use to build low-latency music applications on Windows 11.

This release targets professional musicians and audio software developers who require high-precision timing and expanded device control. The update includes a new USB MIDI 2.0 class driver and a settings app for managing connected hardware. Users must be on Build 27800 or higher in the Canary Channel to access these features.

Multiple apps use one device

The update solves a decades-old limitation by enabling multi-client access for MIDI devices. Under the old MIDI 1.0 model, the first application to open a MIDI port claimed exclusive control over it. If a user opened a digital audio workstation (DAW) and then tried to open a standalone synthesizer app, the second app would fail to see the hardware.

The new Windows MIDI Services acts as a central hub that distributes messages to multiple applications simultaneously. This allows musicians to route a single MIDI controller to several different software instruments at once. It also enables custom MIDI routing utilities to run in the background without blocking the primary DAW.

Microsoft also added the ability for users to assign custom names to MIDI ports. Previously, Windows often displayed generic or confusing names for MIDI hardware, especially when multiple identical devices were connected. Users can now rename these ports in the settings to keep their studio setups organized.

New drivers improve hardware communication

Microsoft introduced a new USB MIDI 2.0 class driver named usbmidi2.sys to support the latest hardware. This driver handles the bidirectional communication required by the new protocol. It allows the computer and the musical instrument to negotiate features and configurations automatically.

Backward compatibility remains a priority for the Windows audio team. The system retains the older usbaudio.sys driver to ensure that legacy MIDI 1.0 hardware continues to function. Microsoft confirmed it fixed several long-standing bugs in the legacy driver to improve stability for older gear.

By default, the OS assigns MIDI 1.0 devices to the older driver to prevent breaking existing workflows. However, power users can manually move devices to the new driver stack through the device manager. This flexibility ensures that 40 years of musical hardware remains compatible with the modern operating system.

Comparing MIDI 1.0 and 2.0

The leap from the original 1983 specification to the 2020 standard introduces significant technical improvements. While MIDI 1.0 was a one-way street, MIDI 2.0 creates a conversational link between devices. This allows for "Property Exchange," where a device can tell the software exactly what knobs and sliders it has available.

The resolution of musical data has also increased dramatically. Velocity and controller values are no longer limited to small integers. The new protocol supports:

• 32-bit resolution for all controller messages, compared to 7-bit in the original spec.
• 256 MIDI channels per group, expanding far beyond the original 16 channels.
• Jitter reduction timestamps that ensure notes play back with microsecond precision.
• Bidirectional communication for automatic configuration and "Profiles" that map controllers to specific functions.
• Backward compatibility that allows MIDI 2.0 devices to fall back to 1.0 when connected to older systems.

These specs mean that electronic instruments can now capture the nuance of a human performance more accurately. The increased bit depth eliminates "stepping" sounds when a musician slowly turns a filter knob or moves a pitch bend wheel. It brings the digital protocol closer to the feel of analog hardware.

Better performance for professional musicians

The new Windows MIDI stack runs as a system service rather than living entirely in the kernel or the application layer. This architectural shift reduces the processing overhead for the CPU. It also prevents a single crashing application from taking down the entire MIDI subsystem.

Microsoft designed the new service to be extensible. This means third-party developers can write "transforms" or "plug-ins" that sit directly in the MIDI path. A developer could create a system-wide transpose tool or a complex MIDI filter that works across every piece of music software on the computer.

The MIDI 2.0 specification also includes "Profiles." These are sets of rules that define how a device behaves for a specific task, like a "Drawbar Organ" profile or a "General MIDI" profile. When a device and software both support a profile, they configure themselves instantly without the user needing to map any controls manually.

A focused tool without AI

The announcement from Pete Brown and his team focused entirely on technical utility and performance. Unlike almost every other recent Windows 11 update, this release does not mention Copilot or AI. It represents a "pro-user" focus that prioritizes low-latency throughput over generative features.

Musicians have long criticized Windows for its complex audio and MIDI handling compared to macOS. This update aims to close that gap by providing an "inbox" solution that works out of the box. It eliminates the need for many poorly written OEM drivers that have historically caused "Blue Screen of Death" errors or timing jitter.

The Windows MIDI Services project is also open source. Microsoft hosts the development on GitHub, allowing the community to report bugs and contribute to the code. This transparency is rare for core Windows components and suggests a long-term commitment to the music production community.

The preview is currently limited to the Canary Channel to gather data on hardware compatibility. Microsoft has not yet announced a specific date for the general release to all Windows 11 users. However, the presence of a functional preview suggests the technology will move to the Dev and Beta channels later this year.