First, what is the occasion, and how is the clientele dressed ? ... I don't necessarily want to be wearing a tux at a pool party unless everyone else is 'black tie' ...
Generally its:
Weddings - rare nowadays except for cocktail hours/parties - tux
Formal Functions - tux
Country Clubs - depending on the event - tux or shirt and tie (tonight is a black suit, nice shirt and tie)
Piano Lounge - again, depending on venue & clientele - blazer, shirt, tie, or open shirt -
Outdoor - Dockers (should I get a sponsor fee for that?!? ) or Bermuda style shorts ... sport shirt
t.