During their Sunday show at Fenway Park in Boston, Foo Fighters were joined by Joe Walsh in their cover of “Rocky Mountain Way.” The song was written by Walsh in 1973 with his band Barnstorm and later released on Walsh’s solo second solo record, The Smoker You Drink, the Player You Get.

Loudwire reports the collaboration was part of a string of covers by Foo Fighters including The Ramones’ “Blitzkrieg Bop,’ in which Grohl invited his orthopedic surgeon, Dr. Lou Schon, onstage to sing, and a Queen/Nirvana mashup of “Under Pressure” and “Smells Like Teen Spirit.”

The cover is part of a long history of collaborative work between the artists. According to Ultimate Classic Rock, Walsh and Grohl performed “While My Guitar Gently Weeps,” during the Grammy salute to the Beatles in 2014, and worked together on the song, “Outside,” from the 2014 Foo Fighters’ album, Sonic Highways.

Foo Fighters are currently on tour in North America in support of 2017’s Concrete and Gold, with an upcoming two-night finale July 29 and 30 at Chicago’s Wrigley Field. After that, the band will take the month of August off before the next leg of their tour beginning in September.

After more than 20 years and nine studio albums, Alternative Nation reports Grohl recently spoke about the group’s longevity, saying, “We are like brothers. It sounds trite but it’s true. Imagine being on a family trip for 20 years. That’s what it’s like being in the Foo Fighters.”

Watch footage of Foo Fighters cover “Rocky Mountain Way” with Joe Walsh.