Lady Gaga posts Instagram picture of her and RedOne in studio together
Lady Gaga has sent her fandom into meltdown with a picture of her and RedOne back in the studio together.
The pop star posted the image of the pair on Instagram.
RedOne produced some of the biggest tracks on Lady Gaga's debut album including Just Dance, Poker Face and Love Game.
The duo also worked together on the number one follow-up album Born This Way, but the producer was missing from the singer's 2013 effort Artpop.
Artpop debuted at number one in the UK and US.
But although it sold more than 750,000 copies in the States, her previous albums were far more commercially successful.
Born This Way shifted more than two million copies in America, while The Fame sold more than three million.
Some critics put Artpop's underwhelming success down to RedOne's absence.
At the time the singer said she was "betrayed" by people around her, resulting in the delays and problems she had with the album.