Well let’s see...
My school has a very musically talented group of students. Unfortunately we have a shrinking band and a disorganized band director (no offense meant to him, he's a great guy). But on Friday (April 30th) we had a Spring Concert and he waited until about last Tuesday (April 20th) to start preparing for it. For jazz band, both of our usual drummers (who are awesome) quit because of work or sports, so he had to find a new guy. In addition to that he waited until 3 days before the concert to start a fourth Concert Band song. And all of the drummers except for our section leader were put into a separate class from the concert band. So we had no idea what was going on. Basically crap hit the fan and we had 10 days to whip up a concert.
For the jazz band problem, one of guys in my percussion class, who's sort of a Rock/Punk/Metal type player volunteered to do jazz band and since I'm a decent set player (not so great with jazz) I went to the afterschool rehearsal to see how good he was. One of the songs given was "Pick up the Pieces" by the Average White Band, he couldn't even play the basic beat, so it wasn't looking good. Then about 48 hours before the concert, when he'd been working on the music for multiple days, the band director suddenly replaced him with our section leader, he got sorta angry and left.
For the Concert Band song, we managed to learn it in 3 days, but on the night of the concert all of the percussion instruments were mixed up, missing, or still attached to the drum set for the jazz band and people were playing parts they were never assigned to, so we had to settle for a sub-par performance. I was surprised afterwards when so many people were complimenting the concert, but oh well.
The lesson I learned here was "logistics".