Tim O'Brien is one of the spearheads of contemporary bluegrass. As co- founder and lead vocalist of Hot Rize and Red Knuckles & the Trailblazers, O'Brien served as a bridge between the traditional sounds of the hill country and the modern styles of bluegrass in the 1980s. Since the band's breakup, O'Brien has continued to expand the music's borders as a soloist, a duo partner with his sister Mollie, and with his band, the O'Boys. O'Brien's songs have additionally been recorded by Kathy Mattea, the Seldom Scene, New Grass Revival, and the Johnson Mountain Boys.

O'Brien's earliest memories of music are the Benny Goodman and Glenn Miller records favored by his parents and the Lawrence Welk recordings played by a Polish housekeeper. A turning point came when O'Brien began listening to a weekly country music radio show, The Saturday Night Jamboree. Discovering that the show was broadcast from a local theater, O'Brien became a frequent audience member and saw performances by Jerry Lee Lewis, Buck Owens, Merle Haggard, and Roger Miller.

Acquiring his first guitar at the age of 12, O'Brien took to the instrument almost immediately. Although he played with numerous high-school rock bands, O'Brien was steered toward country music and bluegrass by Roger Bland, a banjo-playing patient of a girlfriend's psychiatrist father. A former member of Lester Flatt's band, Bland taught O'Brien to play in the three-finger style of Earl Scruggs. O'Brien had earlier discovered that his father had played mandolin banjo in college, and although his father no longer played the instrument, O'Brien bought new strings and learned a few rudimentary techniques. While attending Colby College in Maine, O'Brien began to play mandolin.