I know others will disagree, but I've never found it necessary to stand in line for an hour and a half for a Flower Power concert. We've been to a bunch of them at several F&G shows and haven't had a problem just walking in the back to get a seat maybe 20-30 minutes before showtime. You certainly won't get a seat near the front that way, if that's important to you. But the theater rarely fills to full capacity the way it does for something like the Candlelight Processional. If it's important to you to be absolutely sure you have a seat for a particular group and/or concert time or to be very close to the front, then by all means stand in line to assure that. But otherwise, it may not be necessary.