Its not unusual around here on weeknights. If there are still people signed up who haven't played yet, I'll keep it running. By 10pm, most of the early arrivees are gone. When I was running the OM last year, by 10:15 I'd usually have had everyone play once, and I'd have to try to talk some of the folks who were still hanging out to come up and play a few more songs to fill out the night to 11. Many times, I had to get up and do 20 minutes of songs to an almost-empty place.
They wanted me to run this until 11, but didn't want to pay me any more (or even supply a free dinner!) so I held my guns - besides, it's a 40 minute drive for me, and I'm up for work at 6 in the mornings, so don't want it running late.
In big cities (Boston, for example), the events can run later, but not out in the sticks (Nashua's a city, but barely).
Many OMs start out with a half-hour to hour set by the host which shortens the event anyway, but I warm things up with a quick 3 songs, then get the OMers started. Quick changes between players, too. I've gone to some 'open jams' where it takes 10 minutes between players - with 7 players, that's an hour wasted! I've had trios and even a 5-piece band come, and I get them going in a few minutes.
Only ever heard 2 complaints about the last OM I hosted - once was a comedian (who wan't funny) that came - even though it was a 'no comedy' event, and he got pissed off when no one laughed and ended his act before I could; the other was a guy who was a real 'diva' and didn't like the house PA system (of course the fact that his self-made guitar and dual source preamp didn't sound very good had nothing to do with it...)
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