While most people are pretty good at keeping a conversation going, even in a loud, crowded room—something researchers call the cocktail party effect
—you can help your guests by setting the music to an appropriate level. Bentley Meeker
, who runs his own special-events lighting and production company in New York City, tries to play songs 20 to 25 percent lower than the average conversation. (Forgot your sound-o-meter? Just carry the stereo remote in your pocket, if it's small enough, and adjust the volume if you notice you can't hear the person you're talking to.) Up-tempo music is sometimes recorded at higher volumes—so that means as most hosts shift to Lady Gaga as the evening goes on, they may not have to turn up the stereo to get people dancing.