This candid documentary about Merle Haggard includes interviews with Willie Nelson, Kris Kristofferson, Ray Price, Dwight Yoakam, Lucinda Williams and Allison Krauss. The film reveals how the hardscrabble people with whom Haggard was raised -- his juvenile delinquency and incarcerations -- still inform his creativity and perspective. He hopped his first freight train at the age of 10, became a chronic truant and drinker and was locked up some 17 times as a youngster. Serious criminal charges followed and Haggard was an inmate in the audience in 1959, when Johnny Cash gave his New Year's Day concert in San Quentin -- and, as he's said repeatedly, "my life changed forever. " We have followed Haggard on camera for the past two years -- at home on the ranch and on tour at concerts. A kind of wandering troubadour, who's led his band The Strangers since 1965, Haggard is known as a singer's singer and a guitar player's guitar player -- his voice, his finger picking and his interpretations are like none others. At 72, he recently survived major lung surgery and is now in top physical shape, full of creative juices and hitting new artistic and commercial highs. His expressed concern for keeping his music honest in a changing industry and in a changing world is palpable.