MIDI Monitor
By Snoize
MIDI Monitor displays incoming MIDI messages on macOS. It is useful for diagnosing controller behavior, checking channel assignments and observing the data sent by a keyboard or other device. It does not turn MIDI into sound. Filtering the displayed message types can make a specific problem easier to inspect, especially when a device sends frequent clock or sensing messages.
MIDI carries performance instructions rather than recorded sound. Confirm the receiving instrument, channel assignments and note mapping when exchanging a file or moving the setup to another computer.