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To be honest, even though the pop star did sing “Misery Business” at a karaoke bar the other night, Rihanna seemed to be in good spirits.

A witness tells OK! magazine, “She looked incredible in a beautiful red dress and stiletto heels.” The source added, “She was cool and mingled…She was happy to sing along with other people on songs like ‘Bust Your Windows,’ ‘Living on a Prayer’ and ‘Before He Cheats.’”

The pop star–who’s rumored to be in town to find an apartment–showed up with a group of six friends, with whom she shared drinks and just generally enjoyed a leisurely night out. It was so much fun, her hair actually started to “raise the roof.”

Gallery Info: Rihanna leaving an office building in New York City.