Lady Gaga Records Duet With Cher

Lady Gaga and Cher recorded their duet "The Greatest Thing" on Tuesday, both singers announced on Twitter.

our editor recommends

Lady Gaga’s Vogue Cover Released, Additional ’60 Minutes’ Footage Leaked

Lady Gaga Reveals 'Born This Way' Cover Art, Revisits Apartment On '60 Minutes'

"Who knew a year ago when I was crying in her arms after she gave me an award, that today we would record a duet. @Cher You are The Greatest," wrote Gaga, referring to Cher presenting her with a "Video of the Year" Moonman at the 2010 MTV Video Music Awards -- when Gaga memorably wore a dress made of meat.

PHOTOS: Grammys Red Carpet

Added Cher, "Can hardly wait 4 GT 2 Come Out! Was XCITED 'Bout Making New cd, But Wasn't Expecting BIG Surprises...& THEN...... SURPRISE ! GAGA ! DUET!"

PHOTOS: Grammys: Top 10 Must-See Moments - Including Gaga's Egg

Cher announced on Twitter that the Gaga-penned track will be released in September.

"I wrote that song a long time ago, and I've never put it on one of my own albums for, really, no particular reason," Gaga told MTV News. "I always write these concept records, and it just didn't fit in. But it's always been, like, this big, massive, beautiful hit record and everyone always says, 'Why don't you put that on your album?' And I said, 'I don't know, it just doesn't fit with everything else."

PHOTOS and VIDEO: MTV VMAs: Video of the Year Nominees

"Cher heard the song and loved it and wanted to do it together. And I said, 'F--- yeah, it's Cher!" Gaga went on. It will be the lead single off Cher's 26th studio album.