Lady Gaga, Cher Lady Gaga, Cher

Lady Gaga and Cher's long-gestating duet "The Greatest Thing" will see the light of day in September, according to a tweet from Cher (via Entertainment Weekly).

Lady Gaga to release photography book

The song is expected to be the lead single off Cher's next album. No release date or title has been announced, though Cher has previously described the collection as both containing "a little bit more real instruments, like guitars and stuff like that" and then "WAY DANCE." Whether that means she has revised the album's sound over the course of its creation, or she's going for an organic disco vibe remains to be seen.

Cher: I forget to call Chaz "him"

Gaga and Cher began their public association when the latter handed the former the Video of the Year trophy at last year's MTV Video Music Awards. And speaking of the VMAs, Gaga just announced that she'll open this year's ceremony. That will air live from Los Angeles on Sunday, Aug. 28 at 9/8c.

Lady Gaga's meat dress part of Rock and Roll Hall of Fame exhibit

Listen to Gaga's solo demo of "The Greatest Thing" below: