Country superstar Tim McGraw soon might be climbing the charts with his new song penned for a rock-climbing documentary. “Gravity” is an original tune he sings and co-wrote with singer-songwriter Lori McKenna for Free Solo, National Geographic’s film about the only person to scale Yosemite’s 3,200-foot El Capitan without a rope. Check out a featurette on the recording of the song below.

Discovery

The docu is described as an intimate and unflinching portrait of free soloist climber Alex Honnold as he prepares to achieve his lifelong dream: a ropeless climb of the world’s most famous rock. It’s the inspiring portrait of an athlete who challenges both his body and his beliefs on a quest to triumph over the impossible, revealing the personal toll of excellence.

“There are few people who pursue their passion with the fearlessness of Alex Honnold,” McGraw said. “It’s both terrifying and exhilarating to be on that journey with him when you watch Free Solo. Lori McKenna and I wanted the lyric of ‘Gravity’ to be a reminder that fear is a battle fought on a variety of planes, from mental to spiritual to physical. We tend to think ‘fearlessness’ is synonymous with big bold gestures, but there’s also a fragility inherent in risk — and we wanted that to come through.”

The Meru duo of Elizabeth Chai Vasarhelyi and Jimmy Chin directed Free Solo, which premieres this weekend at the Telluride Film Festival before hitting theaters September 28.

Here’s a behind-the-scenes look at the recording of “Gravity,” followed by the Free Solo trailer: