The producer posted the photo on his ig with Gaga and Davidson with the caption "#readytoworkagain #newsound". It looks like Dallas is a famous country singer, he wrote some songs that went to the #1 on the Billboard Country chart (like Huntin', Fishin' And Lovin' Every Day by Luke Bryan); Brian Kennedy is the producer of Disturbia and Close to you by Rihanna. Edit: IHeartRadio wrote an article about it, here's their tweet: