Long known for erotically-charged performances, Prince was a curious halftime choice only three years post-Jackson/Timberlake. While he did wield that purple unpronouncable-symbol-shaped guitar in an unabashedly phallic way, the ecstatic genius of Prince's performance was the way he actually played the instrument. The diminutive rocker left that testosterone-soaked stadium full of football fans howling approval after powering through his own classics ("1999," "Let's Go Crazy") and the classics of others ("Proud Mary," "All Along the Watchtower"). The explosive coda was his own "Purple Rain" -- delivered, complete with singalong, as it actually rained. Before that gig, how many casual rock fans knew Prince was a guitarist who could be spoken of in the same breath as Hendrix or Clapton?