http://watchawardshows.com full show Usher Ludacris performance So So Def 20th Anniversary Live [2013] Usher Ludacris performance So So Def 20th Anniversary Live [2013] Usher Ludacris performance So So Def 20th Anniversary Live [2013] Usher Ludacris performance So So Def 20th Anniversary Live [2013] Usher Ludacris performance So So Def 20th Anniversary Live [2013] Usher Ludacris performance So So Def 20th Anniversary Live [2013]