MIDI 2.0 introduces higher resolution and more precise control compared to MIDI 1.0, making it ideal for advanced music production tasks. It was officially introduced in Linux kernel 6.5. To enable MIDI 2.0 support on Linux, you'll need to configure your kernel and ALSA (Advanced Linux Sound Architecture) subsystem properly. Here's how to set it up.

Kernel Configuration for MIDI 2.0

Step 1: Ensure your Linux kernel is version 6.5 or newer, as earlier versions lack MIDI 2.0 support. You can verify your kernel version by running uname -r in the terminal. If your kernel is older, you'll need to update it to 6.5 first.

Step 2: Configure your kernel to support MIDI 2.0. Open your kernel configuration tool (such as make menuconfig or make xconfig), and enable the following options:

  • CONFIG_SND_USB_AUDIO_MIDI_V2=y – Enables USB MIDI 2.0 devices.
  • CONFIG_SND_UMP=y – Core support for Universal MIDI Packet (UMP).
  • CONFIG_SND_SEQ_UMP_CLIENT=y – ALSA sequencer binding for UMP.
  • CONFIG_SND_UMP_LEGACY_RAWMIDI=y – Enables legacy raw MIDI device support.

Save your kernel configuration and compile your kernel. Once compiled, reboot into the new kernel.

Accessing MIDI 2.0 Devices on Linux

Step 1: After rebooting into your new kernel, connect your MIDI 2.0-compatible USB device. Linux will automatically detect it and create a new raw MIDI device at /dev/snd/umpC*D*, distinct from the MIDI 1.0 device naming convention. This distinction helps prevent confusion for legacy applications.

Step 2: Verify your device is correctly recognized by inspecting the proc filesystem. For example, run cat /proc/asound/cards to list your sound cards, and cat /proc/asound/card*/midi* to view detailed MIDI endpoint information.

Step 3: To test incoming MIDI 2.0 packets, use hexdump on the UMP device. For example, run hexdump -C /dev/snd/umpC0D0. This command will display incoming MIDI 2.0 packets directly in a hexadecimal format.

Using ALSA Sequencer with MIDI 2.0

Step 1: ALSA sequencer now supports MIDI 2.0 devices natively. Verify your ALSA sequencer clients by running cat /proc/asound/seq/clients. MIDI 2.0 devices appear clearly labeled with their protocol version.

Step 2: To capture MIDI events from your device, use the command-line utility aseqdump. For instance, to listen to MIDI 2.0 events, run aseqdump -u 2 -p 20:1, where 20:1 is the port number of your MIDI 2.0 device.

Step 3: ALSA automatically converts MIDI events between MIDI 1.0 and MIDI 2.0, allowing seamless integration of legacy and modern MIDI applications. No manual conversion is necessary.

Troubleshooting MIDI 2.0 on Linux

If you encounter issues with device detection or functionality, consider these troubleshooting tips:

  • If your device misbehaves with UMP inquiries, disable UMP probing by adding midi2_ump_probe=0 to the snd-usb-audio module options.
  • If you want to revert your device to MIDI 1.0 mode temporarily, add midi2_enable=0 to the snd-usb-audio module options.
  • Check kernel logs with dmesg | grep usb-audio to review device initialization messages.

Advanced MIDI 2.0 Configurations

For developers and advanced users, Linux also provides a MIDI 2.0 USB gadget driver for prototyping. You can create virtual MIDI 2.0 devices using the USB gadget framework for testing and development purposes by checking out the MIDI Association's technical guide.

With MIDI 2.0 enabled, Linux users gain access to higher-resolution controls and improved device interoperability. By following these steps, you can successfully configure your system to take full advantage of MIDI 2.0's advanced capabilities.