She will join husband Jay-Z, Rihanna and U2’s Bono and The Edge in London for the event, airing Friday at 8 p.m. ET/PT.

Beyoncé has been added to the bill for the “Hope for Haiti Now: A Global Benefit for Earthquake Relief” telethon, airing Friday at 8 p.m. ET/PT, upping the star wattage for the already massive event.

Music performances from “Hope for Haiti Now” will be available for purchase and download on the iTunes Store. Beginning on Friday, iTunes customers will be able to exclusively pre-order both the Hope for Haiti Now full performance album ($7.99) and the full two-hour video telecast ($1.99). Pre-orders will be delivered in the days following the telethon. Individual audio performances will also be available for purchase and download for 99 cents each in the days following the telethon. Apple, the record labels and the artists will donate their share of the proceeds to Haiti relief funds managed by “Hope for Haiti Now” charities.

The singer will join husband Jay-Z, Rihanna and U2’s Bono and The Edge in London to help raise funds for Haiti in the wake of last week’s devastating 7.0-magnitude earthquake. Justin Timberlake, Bruce Springsteen, Taylor Swift, Mary J. Blige and more artists will also perform during the two-hour telecast.

George Clooney, who helped organize the event with MTV Networks, will helm the proceedings in Los Angeles, while Wyclef Jean and CNN’s Anderson Cooper will join in from New York and Haiti, respectively.

A number of notable acts have confirmed their participation for the telethon, which will air commercial-free across MTV, VH1, ABC, CBS, NBC, FOX, CNN, BET, the CW, HBO, CMT, PBS, TNT, Showtime, Comedy Central, Bravo, E! Entertainment Network, National Geographic Channel, Oxygen, G4, Centric, Current TV, Fuse, MLB Network, Epix, Palladia, SoapNet, Style, Discovery Health and Planet Green. Canada’s CTV, CBC Television, Global Television and MuchMusic also will air “Hope for Haiti,” as will BET International, CNN International, National Geographic and MTV Networks International, making the event available in 640 million homes worldwide.

Facebook and Twitter are the official social-media partners for the telethon. All donations will benefit Oxfam America, Partners in Health, Red Cross, UNICEF and Wyclef’s Yele Haiti foundation. The Clinton Bush Haiti Fund and United Nations World Food Programme will also benefit from the telethon’s efforts, as aid will be split evenly among each organization’s relief programs for the ravaged island.

Expected highlights from the telecast include U2’s Bono and The Edge joining Jay-Z and Rihanna in London for a one-of-a-kind performance. Kid Rock, Keith Urban and Sheryl Crow are among those who will appear in Los Angeles, and Springsteen, Blige and Shakira are set to take part in the New York portion of the show.

Jay-Z has already staked a claim as the next King of New York with “Empire State of Mind,” but thanks to a new ranking in Forbes magazine, he can now claim regal status in Hollywood as well. Jay and wife Beyoncé topped the magazine’s list of Hollywood’s top-earning couples thanks to a combined household income of $122 million between June 2008 and June 2009, acing out such fellow power duos as Brangelina, Will Smith and Jada Pinkett Smith and David and Victoria Beckham.

The combination of Jay’s musical empire, Beyoncé’s chart-topping hits, movie roles and clothing lines and endorsement deals for both with companies including Budweiser and American Express helped the couple rake in more than any other power pair, married or unmarried, in entertainment. In case anyone in the household is keeping score, Beyoncé out-earned Jay $87 million to $35 million. It was their second year at #1, after snatching the top spot last year with a combined haul of $162 million.

Way behind in second place was longtime couple Harrison Ford and Calista Flockhart, with a combined $69 million, most of it from Ford’s $65 million paycheck for “Indiana Jones and the Kingdom of the Crystal Skull” and Flockhart’s pay for the TV show “Brothers & Sisters.”

Another unmarried pair, Brad Pitt and Angelina Jolie, came in third with $55 million, thanks to hits like “Wanted” and “The Curious Case of Benjamin Button,” one of Pitt’s highest-grossing movies ever with $334 million worldwide. The other couples in the top five were Will Smith and Jada Pinkett Smith ($48 million) and David and Victoria Beckham ($46 million).

Among the other names on the list: new “American Idol” judge Ellen DeGeneres and her partner Portia de Rossi ($36 million), Tom Hanks and Rita Wilson ($35.5 million), Jim Carrey and Jenny McCarthy ($34 million), Tom Cruise and Katie Holmes ($33.5 million), Coldplay singer Chris Martin and Gwyneth Paltrow ($33 million), Sarah Jessica Parker and Matthew Broderick ($29 million) and Tim McGraw and Faith Hill ($28 million).

The figures in the story were based on interviews with managers, agents, producers and lawyers, who provided a picture of what the stars earn from movies, touring, album sales, sports contracts, clothing and perfume lines and endorsements.

Beyonce helped husband Jay-Z celebrate turning 40 in style with a star-studded 1920s-themed party.

The bash, held at Casa de Campo in the Dominican Republic, was attended by over 60 guests including Kanye West and girlfriend Amber Rose, Sean ‘Diddy’ Combs and girlfriend Kim Porter, Alex Rodriguez and Kate Hudson, Alicia Keys, Warner Music chief Lyor Cohen and designer Tory Burch, The New York Post reveals.

A source said: “Diddy gave a toast and Jay-Z’s friends also put together a video saying how much they love him.”

The entertainment included deck-spinning from DJ Cassidy, synchronised swimmers, fireworks and an impromptu performance of Empire State Of Mind by Jay-Z and Alicia Keys, and partying went on until 5am.

The next morning hostess Beyonce held a surf-and-turf brunch for guests at the luxury villa where she and Jay-Z were staying.