Summerfest attendees in Wisconsin got a special treat this year, when young duo Dan + Shay joined country vet Keith Urban for a unique performance of his heart string-tugging hit “Tonight I Wanna Cry.”

The video captures the three musicians rehearsing together before the performance in an intimate behind-the-scenes moment. The guys run through the song on the tour bus, Urban on one side showing the duo how it’s done, and Dan + Shay on the other. After the first verse, the guys join in for perfect three-part harmony, adding even more texture and emotion to the touching tune.

The camera follows the band getting ready to go onstage before sharing a glimpse of the actual performance, where Shay pulls out all the stops with a stunning vocal run. Fans ate it up, knowing they were getting a potentially once-in-a-lifetime performance.

Urban released “Tonight I Wanna Cry” in 2005 as the fifth single from his album, Be Here. The song resonated with fans, and it went to no. 2 on the Billboard Country Airplay chart.

“We were in the basement of my pal’s house on a really gloomy day,” Urban recalls of the inspiration for the song, which he co-wrote with Monty Powell. “That was pretty easy to write, unfortunately, because it’s where I was at."

The artist recently released his latest single, “John Cougar, John Deere, John 3:16,” which, despite its unconventionally long title, is making an impact. The song is the first single off Urban's yet-to-be-released new record, and has already reached No. 13 on the Billboard Hot Country charts. He played the song for the first time on TV at the 2015 CMT Music Awards, and recently put out the lyric video for the new tune.

“It connected in the way I hoped it would,” Urban says, “so I think that’s probably what had all of us start thinking maybe that’s the first song we should get in the studio and work on.”

Dan + Shay have been promoting their latest single “Nothin’ Like You,” and released its music video earlier this week. It already has more than 35,000 views on YouTube.

Both artists are on tour this summer around the country.

The Unlikely Way Keith Urban Chose His New Single

See Keith Urban and Other Stars as Kids