How Many Songs does a band typically play?

How many songs does a band typically play throughout the night? We have a 4.5 hour reception and I was just wondering approximately how many songs we should be picking?

I know it is early for us, but my band emailed me and asked if we had any special requests to let him know so they could start learning them! (I thought that was so great of them by the way - they are my FH's favorite wedding vendor so far!)!

Thanks in advance!!!!!