public performance video release
 

Can anyone point me to a source for language that can be posted for a live club-concert video shoot, that clearly states that the event is being videotaped? I've seen it done various ways, for instance, a posterboard on an easel at the club entrance or similar. I'd like some help on exactly what the language should say.

Also, should it be announced to the audience before the perfomance? Any tips on this stuff is appreciated.