There’s a door between the world of music and the world of movies, but usually it only opens one way. Musicians like Tim McGraw and Dwight Yoakam have been given the chance to become credible actors without much resistance, while actors who want to make records are routinely presumed to be dabbling out of vanity. That may be changing. Actress Zooey Deschanel’s indie-pop duo She & Him earned widespread critical acclaim last year, and now veteran movie actor Kevin Costner offers up an appealing debut effort as a country artist. The star of Bull Durham and JFK has been singing as long as he’s been acting, and it shows in his confidence behind the microphone. He has a ringer on his side in Modern West guitarist John Coinman, who handles most of the songwriting duties here and co-produces with Teddy Morgan. But that wouldn’t matter if Kevin didn’t deliver Untold Truths’ tales of middle-age confusion and wanderlust with a natural charm that makes one hope there are more truths to be told.