Johns PkI/Splash News Online
celebrated her 29th birthday with a dance party at The Darby in N.Y.C. alongside famous pals like Diddy
, an expectant Alicia Keys
and Kanye West
. Hubby Jay-Z
organized the private bash, while DJ Cassidy spun tunes, including Stevie Wonder's version of "Happy Birthday," which was played shortly before cake was served. There was also a jazz band, and a source says the party was "perfect" and "very intimate."