Monitor MIDI track without recording

How can I monitor an externally sequenced MIDI track without actually recording?
I have a hardware sequencer* connected to a MIDI track in Ardour4.
If I play live pads/keys on the hardware, with Rec enabled on the track, I can hear what I play, without Ardour transport rolling.
But I can’t hear sequenced output from the hardware until I enable global Rec in Ardour, and start actual recording by hitting Ardour/Play.
(The hardware is slaved to Ardour)
If I hit Ardour/Play without enabling global Rec, I can see the sequenced audio in the individual track meter, but it is not routed to the Master track, and I can’t hear it.
How can I monitor the incoming hardware sequence on the MIDI track in just Play mode, as well as in actual recording?
*Arturia Beatstep Pro