[2] Duffey learned to play the mandolin, dobro, and guitar, in addition to his tenor singing voice.
[7] In 1957, he worked at radio station WFMD in Frederick, Maryland partnered with Charlie Waller to fill in for other musicians.
As a member of the Country Gentlemen, Duffey was inducted into the International Bluegrass Music Hall of Honor in 1996.
[2] Two months after his induction to the International Bluegrass Music Hall of Honor, Duffey was hospitalized in Arlington, Virginia after complaining of chest pains.
[3] A biography, John Duffey's Bluegrass Life: Featuring the Country Gentlemen, Seldom Scene, and Washington, DC, by Stephen Moore and G. T. Keplinger, Foreword by Tom Gray, was published in 2019 (Booklocker).