On a wintry evening in late November, Karen O celebrated her 30th birthday by throwing herself a party in the city she had fled. Raised in the New Jersey suburbs, Karen spent her formative years in New York City, crafting her identity through cherished postadolescent rituals: going to college, dancing at clubs, drinking in bars, and starting bands with people she'd meet at clubs and bars. One of those chance encounters, with a Bard graduate named Nick Zinner, turned into the Yeah Yeah Yeahs, who, in a New York minute, became poster children for the Great Gotham Rock Resurgence of the Early Aughts. (Whattup, Julian!?) So, in 2004, when Karen suddenly packed up and moved to -- of all freakin' places -- Los Angeles, she shocked her friends, family, and bandmates.