Girls Aloud is the leggy quintet that beat out rival boy band One True Voice for the grand prize during the November 2002 finale of Popstars: The Rivals. A scion of existing U.K. reality shows like Popstars and Pop Idol (which itself spawned American Idol), Rivals followed a similar formula, with one essential twist. After spending weeks building its bands with the normal round of tryouts, kick outs, voting, and drama, drama, drama, the program pitted its final products against one another in an ultimate pop-reality showdown…