It was pure madness at the Rolling Stone/Verizon Wireless pre-VMA party last night in New York. And by madness, we mean Whitney Houston, who was spotted grooving to the tunes of the night’s performer, John Legend, in the upstairs balcony at NYC’s Bowery Ballroom. In any case, Legend slayed the packed-to-the-gills club, powering through hits like “Ordinary People,” and premiering never-performed songs from his upcoming album, the RS-tested and approved disc Once Again. Also in effect: singer-songwriter Gavin DeGraw, actress Shannon Elizabeth, and that guy DJ AM, who hobnobbed with house DJ Samantha Ronson. We tried to rock out but kept getting bumped by gaggles of drunk models and cocktail waitresses giving platters of mini-cupcakes the hard sell. ‘Twas a magical night indeed.