Nicole Richie and Alicia Keys
and Alicia Keys
added even more stunning star power to Zac Posen
's front row. Posen created quite the formal affair as five pianists (a brother and sister group called 5 Browns), clad in tuxedos and ball gowns, took to the runway performing classical ballads on Steinway grand pianos while models elegantly floated down the catwalk in whimsical chiffon, metallic and floral-print gowns.