No stranger to South Korea’s music scene, Gallant shocked the crowd during his performance at Icheon’s Jisan Valley Rock Festival on Saturday (July 29).

The R&B singer was joined by South Korean pop-soul singer Lee Hi during his headlining performance at one of the festival’s main stages. Lee sang along to "Skipping Stones," filling in for Jhene Aiko. “I saw a clip of [Lee] performing one of my favorite songs by Jazmine Sullivan and I thought that her voice was incredibly soulful,” Gallant told Billboard via email.

The pair met in a bar in Seoul’s Itaewon neighborhood, and decided on the surprise performance at the Valley Rock Festival, one of South Korea’s biggest music events of the summer.

----Skipping stones---- A post shared by @leehi_hi on Jul 29, 2017 at 6:00am PDT

Gallant also shared the stage with Epik High’s Tablo for a rendition of their January release, “Cave Me In.” (Eric Nam, who also worked on the track, was performing in Singapore the same day and unable to join them.)

“I think [South Korea] is a fascinating musical landscape, I think that a lot of people in America aren't super familiar with it or don't appreciate it as much as I think they should,” Gallant said.

His latest South Korean festival appearance isn’t the first time Gallant’s performed in Korea, and he expressed willingness to working with other K-pop artists in the future. “Every time I've played a show [in Korea] it's always been the biggest show I've ever played at that point,” said the singer, who hoped that the Jisan Valley performance would be “the greatest experience of my life thus far touring.”

Along with collaborating with several popular Korean musicians, the Grammy-nominated Gallant has also performed at Korean music award shows in the past, and he’s keeping his eye on burgeoning artists in the scene.

“I have always been a big fan of Japanese pop and K-pop, and then to experience the indie artists in Korea on top of it, who are creating their own subculture, was something that drew me in and made me want to learn more,” he said.

“Cave Me In” was part of that learning process, with Gallant describing Tablo and Nam, both mainstream artists in South Korea's industry, as inspirations "who have so much to them and to what they do."

Along with Gallant, headliners at the 2017 Jisan Valley Rock Music & Arts Festival included Lorde, Major Lazer, Gorillaz, Nell, Sigur Rós, and Hyukoh.