I did one gig depping for a big band - about 25 strong... the full glen miller, sinatra, micheal buble job.
It was really good fun but hard work - apart from having to play about 45 songs (about 3 hours worth) - you had you keep you eyes on the dots all the time.
My biggest problem was getting lost in the repeats and jumps to codas....especially the ones that arent written down... so I'd make sure you have those sorted at the start - then if you do fall off its easier to get back on.
Otherwise it was great experience - go for it...