POSTED BY STEVEN GAYDOS

Coming down the pike on July 21 courtesy of PBS’ “America Masters” series is one of the best music bio docs I’ve seen in years: “Merle Haggard: Learning to Live With Myself’,” a journey into the heartbeat of a complex songwriter, musican and singer whose place in the history of American country music fits nicely in that pantheon that includes Jimmie Rodgers, Hank Williams and Johnny Cash. Not since “Art Pepper: ‘Notes From a Jazz Survivor’” has a doc so movingly conveyed the pain and personal trauma at the heart of the art. Haggard-0110

Not coincidentally, both docs are driven by the unflinching honesty of the subject, who takes the job of doc protagonist as seriously as composing and performing.

If you only know the Haggard canon from his biggest hit, “Okie From Muskogee,” you’ll be floored by the lyricism and power of Hag’s pen: “Silver Wings,” “Sing Me Back Home,” “Footlights,” “Today I Started Loving You Again,” “The Running Kind,” “White Line Fever,” “Working Man’s Blues” are only a few of his classics. And his work as a vocalist, picker and musicologist is, as the doc notes, an essential link to the origins of country music that few in the cookie-cutter factory that is contempo Nashville can relate to, let alone preserve.

“Learning to Live With Myself” writer-director Gandulf Hennig has one other first-rate music doc under his belt — 2004’s “Fallen Angel: Gram Parson,” about the short, tragic, yet musically fruitful life of that doomed Burrito and Byrd man. Luckily for Haggard, unlike Parsons, he never tried to keep up on the drug front with Rolling Stones (reformed) bad boy Keith Richards. Where Parsons’ demons demolished him in his mid-20s, Haggard, who not only spent many years in the bag and the bottle but also two hard years in San Quentin, is now in his early 70s and still cooking. He puts everything he’s got into his shows and his recordings, as the doc amply reports.Merle-haggard-100

Richards appears in “Learning” — along with other luminaries such as Kris Kristofferson, Robert Duvall and fellow country giant Ray Price — as one of the many valuable voices of appreciation and personal insight into Haggard’s life, oeuvre and raison d’etre. As Keith explains, “Merle is completely not about showbiz. He has things he wants to show you and things he wants to tell you. That’s what it’s all about.”

Follow @Variety on Twitter for breaking news, reviews and more