BY ABBEY WHITE | HollywoodReporter.Com

As part of the 1,500th episode celebration, the actor sang a song that Fallon said he has been pitching to “famous people” for years who all passed.

Kit Harington helped celebrate the 1,500th episode of The Tonight Show Starring Jimmy Fallonwith his own rendition of Train’s “Drops of Jupiter.”

The Game of Thrones and Modern Love star, who recently opened up about his mental healthwhile working on the HBO series, dropped by the late night show to help Fallon deliver a sketch the Tonight Show host and his team have been itching to do for years.

“Guys, tonight is our 1,500th show and, in honor of that, something special is about to happen,” Fallon teased. “Years ago we had an idea for a bit called ‘Straight Up Goes For It.’ It was a simple idea. We wanted somebody to come out and straight-up sing ‘Drops of Jupiter’ by the band Train. That’s it. That’s the whole idea.

Fallon went on to describe the sketch as “our white whale,” revealing that the show had “been pitching it for years” to tons of guests, “famous people that you know and love,” actors who sing in movies, dancers, and artists who “actually have music out.”

“They all passed on it,” he said to audience laughs. “But not tonight. Tonight that changes because we finally have someone who has the guts to do it.”

Before the stage lights came up on Harington, who — with slicked-back hair and in a black suit — sat at a piano covered in flowers and lit candles, Fallon laughed as he admitted the actor “doesn’t play piano by the way and he doesn’t even really know how to sing.”

Both of those things were confirmed as Harington playfully gave his full-throated rendition of the 2001 hit from the band’s sophomore album. The audience responded with cheers before Harington moved them to stand and clap along, earning himself a standing ovation.

After the performance, Harington revealed his hesitations about doing the sketch, which was complicated by the possibility that it “might open up whole new vistas of a career in singing.”

“I had a lot of thoughts when you sent me that. Like, a lot,” Harington said in his sitdown with Fallon. “And the sensible part of my brain, the bit that said, ‘You’re not a singer, you have no connection to this song, it’s of no relevance to anything you’re talking about on the show,’ said don’t do it. But there was another little part of my brain, right? The bit that gets me in trouble, that was like, ‘But what if you’re brilliant?’”

Watch the interview in full below.