What better way to wrap up a tour than with an outdoor, acoustic singalong? Essentially, that's what you'll see in today's Grace & Tony Greenroom Sessions video.

The husband-and-wife duo rounded up tour mates Penny & Sparrow, along with cellist Chris Wilson and violinist Alex Page, for their take on the Christian hymn 'How Great Thou Art.'

"This was the last night of our tour ... and this was a perfect way to end it," Tony tells The Boot. "We had done this song completely acoustic at the last two shows of the tour, and the crowd's singing along was beyond moving."

However, when they went to shoot, there was one small problem: "We wasted time, and the venue was closing before we got the session in," Tony says. So, they improvised.

"As we loaded out, we spotted the well-lit porch of Steverino's [in Duluth, Ga.], and we thought it was perfect," he says. "This spontaneity and camaraderie really captured the essence of the Greenroom Sessions."

The Boot will bring you two new videos in this collaborative series next month, on Aug. 1 and Aug. 15.