As a child, he played tenor banjo but switched to guitar on the advice of his elder brother, record producer Owen.
[4] After graduation, Harold joined the Navy in 1944 and was discharged in 1946, after which he attended George Peabody College (now a part of Vanderbilt University) in Nashville, studying music while accompanying Eddy Arnold and Bradley Kincaid at the Grand Ole Opry.
Bradley's first gig as a session guitarist was in Chicago in 1946 with Pee Wee King and the Golden West Cowboys.
His debut in Nashville was several years later in 1949, and his acoustic rhythm guitar opens Red Foley's 1950 hit "Chattanoogie Shoe Shine Boy".
[3][6][7] Harold enjoyed frequent work as a session musician throughout the 1950s, 1960s, and into the 1970s, performing on hundreds of albums by country stars such as Patsy Cline, Willie Nelson, Roy Orbison, Elvis Presley and Slim Whitman.