Logic Pro X 10.5 - jamming with external instrument over software instrument issue?

[miloszz]

Say I have two tracks - audio in for an external synth and a software instrument (drum machine). The audio in works when input monitoring is enabled, as normal. But if I create a midi or pattern section for the software instrument and then start playing that, I can't get audio in from the external instrument unless I'm actively recording. Am I missing something that would let me do that, so that I can jam over a drum beat to work on a sound before recording?

(This is true in live looping and the regular mode.)

[revvy]

I jam with HW all the time over stuff I've recorded in MIDI.

For HW synths I don't add them as audio tracks, I use 'External MIDI' and tick 'Use External Instrument plug in' box.