Born in San Antonio, Barker got his first guitar at age six, taught himself to play it and was soon singing at school and church events.  He also began to write songs at an early age.  When asked to create a grade-school art project, Barker turned in poetry rather than work within the visual limits of his red-green color blindness.  Those poems eventually became the basis for his first songs.

Those who have recorded Aaron Barker songs include George Strait, Lone Star,  Tyler Farr, Trace Adkins, Aaron Tippin, Tracy Lawrence, Neal McCoy, The Oak Ridge Boys, Granger Smith, Willie Nelson, Chris LeDoux, Dean Dillon and Trent Tomlinson.  Barker was inducted into the Texas Heritage Songwriters Hall of Fame in 2007 and Nashville Songwriters Hall of Fame 2016.