Rihanna has performed for the first time since she was allegedly assaulted by her on/off boyfriend Chris Brown. The "Rehab" singer - who was dressed in a black Dolce and Gabbana power suit - joined Kanye West on stage at the Metropolitan Museum of Art Costume Institute Gala in New York on Monday.

The pair performed a duet of Kanye's song "Say You Will" before Rihanna belted out an emotional rendition of her hit "Live Your Life."

Kanye West's arraignment has been postponed until May 20. The hip-hop artist's lawyer has successfully moved the court date from Tuesday to next month.

West, 31, is charged with vandalism, battery and grand theft, stemming from his scuffle with two paparazzi at LAX in September last year. The "Stronger" hitmaker was seen smashing a photographer's camera to the ground.

Kanye West claims he is the most intelligent rapper in the world. The 31-year-old star refuses get drawn into hip-hop feuds because he would outwit all of his chart rivals.

He said: "I feel like if a rapper disses me, they're just trying to get a rise out of me and get me to play in their field to find some way that they can beat me. I feel like there are a lot of rappers that can beat me in ignorance.

Kanye West faces up to two and a half years in jail following a scuffle with paparazzi. The rapper was formally handed misdemeanor charges of vandalism, battery and grand theft yesterday for the scuffle at Los Angeles airport on September 11 last year.

Kanye's road manager Don Crawley faces the same charges, but two counts of each. The prosecuting Los Angeles attorney's office issued a statement, saying Kanye and Crawley "confronted, and engaged in an altercation with, two photographers."

Kanye West's new girlfriend stars in his next music video. The rapper - who has attended several shows at this week's Paris Fashion Week with Amber Rose - cast the shaven-headed model as a robotic police officer in the promo for his forthcoming single "Robocop," prompting speculation their relationship is a publicity stunt.

A source said: "Kanye's popularity has dipped a little in recent months so what better way to get people interested again than by stepping out with a stunning model - and then casting her in his video. People will be tuning in to see the sexual chemistry."