It's Harold Night at the Upright Citizen's Brigade Theater, and it's yet another great deal from New York's premiere independent comedy venue: $5 gets you 5 shows, each of them the particular take of a particular team on the loosely-structured "Harold" improv show format devised by Del Close. 

I'll leave it up to you to decide whether it's more fun to watch Harold Night with or without knowing what the Harold is, but there's as much disagreement about Close's vision for what it ought to be and the shape it ought to take as there are improvisers.  My favorite  explanation for Close's intent, provided by Kevin Mullaney, is that Close was seeking a format wherein a group could begin from a randomly-generated suggestion and craft a performance which explicates and celebrates the inherent interconnection of all things.  

This is, admittedly, a conveniently vague definition, but it is precisely the reason that Harold Night is so enjoyable.  You'll watch five improv groups put their own spin on the format.  The casts and group names shift from month to month, but certain players have been around the theater for years.  Look for amazing work from Sarah Burns, Jonathan Gabrus, Ellie Kemper, Risa Sang-urai, Ben Schwartz, and Matthew DeCoster.  These performers in particular embody the versatility and intrepid exploration required to wring continued viability and excitement from the Harold structure week after week.