The Oscar-winning actress and Grammy-winning singer was spotted on set Sunday in NYC, where she was in costume as a young Aretha Franklin for the upcoming biopic about the music icon called 'Respect.' Marlon plays her first hubby and ex-manager, Ted White.

In this scene -- which is supposedly set in Harlem during the mid-60s -- you can see Marlon talking to a group of prostitutes, before collecting money and roughing one up a bit. Jennifer (as Aretha) looks on from a waiting car, and when Marlon gets back in ... they share a passionate kiss. Gotta say ... the production value seems to be pretty high here.

BTW, Jennifer was reportedly hand-picked by Aretha before her death in 2018. She probably couldn't have chosen a better person to play her in a movie. Jen's got the chops on both ends to pull it off -- and so far, she certainly has the early Aretha look down.

And, while Marlon usually plays the funny guy, he comes off as menacing and serious here. That jives with the real-life Ted, who's remembered as a notorious Detroit pimp ... who allegedly abused Aretha before they finally parted ways in 1969.