Harley "Red" Allen, born on February 12, 1930, in Pigeon Roost Hollow, Kentucky, was a prominent American bluegrass musician known for his powerful tenor voice and skilled guitar playing. Growing up in the music-rich hills of eastern Kentucky, Allen was influenced by the sounds of the Grand Ole Opry and other jamboree programs. After serving in the Marines, he settled in Dayton, Ohio, in 1949, where he began his professional music career.

In 1952, Allen formed the Blue Ridge Mountain Boys with mandolin virtuoso Frank Wakefield and banjo player Noah Crase. He gained wider recognition in 1956 when he joined the Osborne Brothers, contributing to their influential vocal harmonies. Their song "Once More" became a hit, reaching number 13 on the country charts.

Allen's career included collaborations with notable artists and bands such as the Osborne Brothers, the Kentuckians with Wakefield, and a stint with Flatt & Scruggs. He also performed with his sons in Red Allen & the Allen Brothers. Throughout his career, Allen recorded for several labels, including MGM, Folkways, and King Records, and was known for his innovative harmony patterns and blues-influenced style.

In 1963, Allen performed at Carnegie Hall, and in 1967, he temporarily replaced Lester Flatt in Flatt & Scruggs. He continued to perform and record through the 1970s and 1980s, contributing significantly to the bluegrass genre. Red Allen passed away from cancer on April 3, 1993, in Dayton, Ohio. In 2005, he was inducted into the Bluegrass Hall of Fame, solidifying his legacy as one of the premier bluegrass vocalists of his time.