...start recording a track at a specific marker

I would like to record a guitar piece in a session. However, I want to place a marker at a specific place and then play my song, and have the specific track start recording at that marker.

Is this possible in Ardour?

I believe you’ll want to use punch markers. Here’s a guide I just found. http://briansbedroom.org/ardour/how-to-punch-record-in-ardour/

That’s called Punch-In/Out.
From the little you stated here I would assume you mean Punch-In/Punch-Out recording.
Just Ctrl-Click-Drag in the Loop/Punch line where you want your recording to start/end. Select Punch from the little menu that appears after you finished dragging the mouse.
Finally, click on Punch in and Punch out in the bar below the menu to activate punching in and out.
When you start your recording, only the time between punch-in and punch-out will be recorded.

Hi, thanks for the feedback, both of you. I always wondered what “punch” referred to! Let me try that and get back to you.

Yes, that was it! Thanks!