It's not every day that you get to witness an “American Idol” contestant meeting one of their Idols, but that's exactly what happened late Wednesday night at the Mondrian Hotel's Sky Bar, where Season 9 sixth-place finisher Siobhan Magnus came face-to-face with three guys named Taylor, Zac and Isaac, otherwise known as her favorite band Hanson. Yours truly was there to capture the moment and it was, in a word, magical. Siobhan looked simply dumbfounded upon first sight of Taylor Hanson, and, in fact, the only sentence she managed to string together once a formal introduction got made was: “I don't know what to say!” To which Taylor responded, “Well, let me say this: we're really honored that you feel so inspired and motivated by what we do.” Siobhan spent the better part of the next hour regaling the guys, who were in town to perform on “The Tonight Show,” with stories of her adventures at various Cape Cod-area Hanson shows, including one she had to attend solo, while Isaac and Zac asked about the machinations of “Idol” and complimented Siobhan on her piano playing at the “If I Can Dream” house . Of course, here was a dream moment come true that the four will remember forever