Transfer MIDI information between apps in Audio MIDI Setup on Mac
In Audio MIDI Setup, use the IAC Driver to let MIDI apps transfer information to each other. For example, you might have a MIDI keyboard app send its MIDI data to a MIDI synthesizer app.
To allow MIDI apps to transfer information, you need to set up at least one bus (sometimes referred to as a port) in the IAC Driver. One app uses the bus as a destination to send information, and another app uses it as a source, to receive information.
In the Audio MIDI Setup app on your Mac, choose Window > Show MIDI Studio.
In the MIDI Studio window, double-click the IAC Driver.
In the Properties window, select “Device is online” to turn on the driver.
To set up the ports, do any of the following:
Add a bus: Click the Add button below the list of ports.
Rename a bus: Double-click the bus in the list, enter the new name, then press the Return key.
Remove a bus: Select the bus in the list, then click the Remove button .
Select the bus you want to use to transfer information, then specify the number of MIDI In and MIDI Out connectors.