Alicia Keys has boosted the total raised at her annual Black Ball charity event in New York to over $2.9 million (£1.81 million) after securing a $1 million (£625,000) pledge from a billionaire guest.

The Empire State of Mind hitmaker's big benefit took place at New York's Apollo Theater on Thursday (06Dec12), a month after it was postponed out of respect for the victims of superstorm Sandy.

The gala included a live auction to raise funds for her Keep a Child Alive campaign, which helps youngsters affected by Hiv and Aids, and Keys even agreed to join pharmaceutical billionaire Stewart Rahr on a holiday to South Africa if he bid more than $250,000 (£156,250) for her company.

Rahr declined the offer, but made it up to Keys by donating a massive $1 million to the charity.

Early estimates suggested the Black Ball had raised more than $1.3 million (£812,000), but Rahr's generous sum has pushed the total past $2.9 million.

Whoopi Goldberg hosted the 2012 bash and Oprah Winfrey was honoured for her philanthropy at the event. Keys took to the stage with Bonnie Raitt for a duet of the blues singer's popular ballad I Can't Make You Love Me. Jennifer Hudson and Alabama Shakes singer Brittany Howard also performed.