Bluegrass musician Bobby Osborne, who helped popularize the song “Rocky Top,” died early Tuesday, according to a statement from the college where he worked. He was 91.

Osborne and his brother Sonny made up The Osborne Brothers, and their version of the song “Rocky Top” in 1967 became an official state song of Tennessee, his website said. Osborne was a member of the Grand Ole Opry and the International Bluegrass Music Hall of Fame.

“To say he was a legend falls short of the impact he had on all of us,” said Paul Schiminger, interim executive director at the International Bluegrass Music Association. “An innovative musical pioneer, Bobby set and held the gold standard for bluegrass vocals.”