If you have already recorded all or most of a session, you can re-record *part* of the session in order to "fix up" any issues.
Ardour allows you to record onto the pre-existing tracks, keeping the first take, putting the newly-recorded region over it. Later, you will get to choose the exact points at which the outputted recording is to switch between regions/takes.
Record the session.
Ensure that you have the connections and levels set as they were during the first time you recorded the regions over which you're recording now.
You will need to set the transport location. Choose a place that is before the segment which you want to replace. The performers should probably also start playing before the section to be replaced, so you will need to start well enough in advance that they can pick up the tempo, get in the groove, and then start playing *all before* the part that needs replacement.
Click in the time-line to move the transport.
Ensure that the correct tracks are armed.
Arm the transport.
Start the transport and record the revised section of music.
At some point, you will have recorded everything that you need, and you will want to progress to mixing and editing.
