Meghan Trainor honored tragic singer Christina Grimmie at a gig in New York on Saturday night (11Jun16) by urging fans to belt out her John Legend ballad at the top of their voices.

Grimmie was shot dead by an obsessed fan after a concert on Friday night (10Jun16), and the tragedy was weighing heavy on Trainor as she hit the stage at the BLI Summer Jam in Wantagh 24 hours later.

The 22-year-old dedicated her performance of Like I'm Gonna Lose You to the former The Voice finalist and then invited fans to sing the song with her as a tribute to the dead star.

"If you will please sing it with me as a shoutout to our girl Christina...," Trainor told the crowd. "This one's for her. Let's sing nice and loud."

Grimmie, also 22, was shot and killed by 27-year-old Kevin James Loibl outside the Plaza Live theater in Orlando, Florida, while she was signing memorabilia for fans during a meet-and-greet.

Grimmie's older brother Marcus tackled Loibl to the floor before the gunman killed himself.

Christina finished in third place on season six of The Voice in 2014. Her coach, Adam Levine, has offered to pay for her funeral arrangements.