02/14/2012 AT 5:55 AM ET
A slender Rihanna turned heads in her corset and pants, while Perry could not be missed with her bright blue hair, which matched her dress.
Also there to celebrate Grammy weekend was Ellen Pompeo and her music-exec husband Chris Ivery; Nicole Richie, who shared a moment with The X Factor’s L.A. Reid as he made his rounds; and Sam Ronson and Rashida Jones, who chatted and ate in the packed sunlit back room. Other talent mingling included Kelly Rowland, Michelle Williams, Corinne Bailey Rae, Ne-Yo and Christina Milian.
Jay-Z may not have been present, but plenty of partygoers were rocking blue accessories – in “silent respect,” one was overheard saying – for his newborn daughter, Blue Ivy.
– Kristin Boehm