U2, Jay-Z and producer Swizz Beatz have recorded a song together to raise money for victims of the Haiti earthquake.
U2's guitarist The Edge told Irish radio station 2FM the band "wrote a song, finished and recorded" last week after being contacted about the idea.
The Edge, Bono and Jay-Z, along with Rihanna, are due to appear in London for "a group performance" as part of Friday's Hope For Haiti telethon.
George Clooney's two-hour benefit show will be aired on MTV in the UK.
The Edge told 2FM DJ Dave Fanning over the weekend: "Bono got a call from a producer, Swizz. He and Jay-Z wanted to do something for Haiti.
"So Bono came up with the phrase on the phone and last night we were here, we wrote a song, finished, recorded, and sent it back to them.
"So, that might be the next thing you hear from us."
Swizz Beatz also confirmed the project on his Twitter page, saying: "Me, Bono, Hova [Jay-Z's nickname] have something to say about Haiti. Stay tuned.
"I told you I was working on something amazing for Haiti. They need us!"
It is not clear when the single will be released, or whether the artists plan to premiere the song during Friday's telethon
Jay-Z has played with the Irish rock group before, popping up for a handful of dates on last year's 360 tour, and adding a rap to their hit single Sunday Bloody Sunday during the 2009 MTV Europe Awards.
George Clooney has been organising the Hope For Haiti telethon
Meanwhile, more acts have been added to the bill for the Haiti telethon including Coldplay, who will play at "a London location" alongside Jay-Z.
Kid Rock, Sheryl Crow and Keith Urban will appear in Los Angeles while Haitian-born Fugees star Wyclef Jean, Sting, Mary J Blige, Shakira and Bruce Springsteen will be among performers in New York.
Funds raised will go to Oxfam America, Red Cross, Unicef, Partners in Health and the Yele Haiti Foundation.
The telethon will be screened live in the UK from 0100 GMT on Saturday 23 January.
In the US, the telethon is being screened live without commercials on a number of channels including NBC, ABC and CBS.