This new career biography of Bing Crosby, by Robert Trachtenberg, shows how effortlessly the crooner made it all seem, becoming a fixture on radio, in movies and on TV appearances, while maintaining a less than devil-may-care attitude about it all. This study is a bit too fawning, overall, but it doesn’t skimp on either the achievements (the first singer to use amplification properly in recordings, the one whose “White Christmas” single sold more than any other, ever) or the acerbity. Wait for the final credits on this documentary, and listen closely, to how Crosby ad libs his own lyrics during a botched take in the recording studio. Watch, also, for the real story of how an aging Crosby and a young David Bowie got together to sing a Christmas carol on one of Crosby’s shows – and why Bowie refused to sing “The Little Drummer Boy,” so it turned into a different arrangement altogether. Check local listings.