Ask yourself the following questions, and come up with a one sentence answer.
What do you need to do?
Get familiar with the tunes? Do we get the set order determined? Do we need to work on transitions, see what works next to one another?
Do we need to work on rough spots? Can we identify specific rough spots from the last performance or run through rehearsal?
You should come up with a statement similar to the following, this will give a direction and focus to your rehearsal planning, preparation and execution.
"This rehearsal will be to work out certain rough spots in the following songs, based on our last performance."
'This rehearsal will be to work on our starts, stops, and transitions"
"This rehearsal will be a run through of new tunes with an ear toward what we need to work on in future rehearsals"
You get the picture.