Cody Littlewood was at Brandy’s Piano Bar on the Upper East Side when bartender Joe Ardizzone offered the crowd an angsty treat.

An empty bar is best. You just pick a seat where there's light enough to read, and the bartender comes right over. Then there are the busy nights, when people crush around the bar three deep and getting a drink seems impossible. What kind of supernatural skills are necessary for getting a cocktail on a Saturday night?

"If you don't have a bartender at your party, you're a loser," said a guy whose job is "to get models and Saudi royalty into hot clubs," to an NYT Style reporter at a party in a cramped Williamsburg apartment.