Keira Knightley & Mark Ruffalo: 'Song' Set Smooch!

Keira Knightley and Mark Ruffalo lock lips on the set of their upcoming flick Can A Song Save Your Life? on Thursday (July 19) in New York City.

The 27-year-old actress and her 44-year-old co-star are joined in the flick by Maroon 5 frontman Adam Levine and Hailee Steinfeld.

PHOTOS: Check out the latest pics of Keira Knightley

The drama centers on a businessman who falls for a young singer-songwriter and will hit theaters next year.

10+ pictures inside of Keira Knightley and Mark Ruffalo on the set of Can A Song Save Your Life?…