Beyoncé Knowles was spotted busting a groove at an album launch for one of Jay-Z's old rapper rivals.

The stunning songstress and husband Jay took time out from being parents to Blue Ivy to attend an event for Nas' new album, Life Is Good.

The rapper is a former rival of Jay's, but any ill feelings were put aside as the high-profile pair joined in festivities for the star's latest musical offering.

Beyoncé - who was sporting braided hair at the event - was seen "dancing to the music" at the Moët Rosé Lounge 2012 on Monday night, according to the New York Post.

The celebrations started with a dinner followed by a "packed out after-party".

Other celebrity guests included Busta Rhymes, Swizz Beatz and Tyson Beckford.

Jay-Z and Nas were embroiled in a high-profile hip-hop feud which started after both fought for the title of 'King of New York' following the death of The Notorious B.I.G.. Their differences were formally resolved in 2006, when Nas signed with Def Jam while Jay was still president.