Barbara Kopple and Cecilia Peck have crafted an insightful and heartfelt look at the experiences of the Dixie Chicks over the last three years, chronicling the often bizarre consequences of singer Natalie Maines' anti-Bush wisecrack on a London stage. Maines' statement is captured in "Dixie Chicks: Shut Up and Sing," as are the meetings where they plot how to circumvent the core country audience and, eventually, how to reroute a tour and cancel shows due to poor ticket sales. It's the rare thorough documentary on a musical act whose dilemmas are faced in the here and now, one that should...