Test your MIDI setup - Apple Support

Use the Audio MIDI Setup app on your Mac to test your MIDI setup.

MIDI Translator Pro – Bome Software

Midi stopped working with iOS 15.4 - Apple Community

Troubleshooting USB MIDI devices on Mac : M-Audio

MIDI controllers: What are they? How do they work? - RouteNote Blog

Audio MIDI Setup for Mac

Apple Support, Logopedia

Set up HomePod or HomePod mini - Apple Support

How to Connect a MIDI Controller to the iPad

iPadOS 15 now available to all iPads supported by iPadOS 14