Beyonc Knowles has shown off her impressive post-pregnancy body in her first public appearance since having a baby.

The 30-year-old singer who gave birth to daughter Blue Ivy on January 7 was out in New York City last night to support her husband Jay-Z.

She looked stunning in a tight-fitting red Alice by Temperley dress teamed with oversized gold hoop earrings and Christian Louboutin platform heels.

The new mom beamed with happiness as she arrived at Carnegie Hall to watch her husband Jay-Z perform with a full orchestra.

Jay-Z was thrilled to have his wife in the audience and looked visibly choked up when he performed Glory the song he wrote for his new baby girl.

"You could tell Jay is over the moon," a source told Us Weekly. "He asked the crowd if there are any proud parents out there. Then after he said, 'I didn't think I was gonna make it through that one - that was tough.'"

During the concert, Jay-Z was joined on stage by Alicia Keys and the pair thrilled the crowd by performing their hit duet Empire State of Mind.

Nas also performed with Jay-Z during the benefit concert.

After the show, a host of stars attended the official after-party at Jay-Z's 40/40 club. Beyonc was clearly enjoying herself and spent time chatting to the other guests.

"She made a much bigger effort to say hello to nearly everyone, making rounds around the whole club before joining Jay-Z and guests in the VIP room," an onlooker revealed.

Beyonc arrived at the bash just before midnight and greeted her rapper spouse by throwing her arms around him in the middle of the club. Jay-Z relaxed after his impressive performance by sipping champagne and snacking on celery in the VIP area.

Jay-Z performed for the first time at Carnegie Hall to raise money for his Shawn Carter Scholarship Foundation and The United Way of New York City, which gives talented students financial assistance to attend college.