A documentary called The Singing Revolution makes its Dallas debut at the Angelika this Friday, June 13. I have to admit when I sat down to watch it I wasn’t sure I possessed the focus required for a historical documentary — I’d had a trying day. Initially the narrator seemed to be going on and on about singing and what singing meant to the small country of Estonia, and the singing didn’t seem all that remarkable in and of itself. But it didn’t take long for the movie to grab me — by the end I wanted to download the Estonian national anthem (‘Land of my Fathers, Land that I Love’) and play it loud and sing along.