This included the role of Tommy in Meredith Willson's The Music Man, and a court jester in the school's madrigal dinner.
While a high school senior, Barr learned that Richard Linklater was planning a film about football in Austin, Friday Night Lights.
Although this movie ended up being put on hold for another two years and Linklater was replaced by Peter Berg as director, Barr made some favorable impressions.
Half a year after the filming of Levelland ended, in January 2003, Barr moved to Los Angeles, where his first acting job was a scene on the television show ER.
Between 2009 and 2010, he guest starred in many TV series, such as Castle, Trauma, Friday Night Lights,[7] and CSI: Crime Scene Investigation.
[11][12] In 2012, Barr assumed a leading role, starring in the Kevin Costner miniseries Hatfields & McCoys for the History Channel.