A behind-the-scenes look at the Boston Pops Fireworks Spectacular - the annual July 4 celebration where 400,000 people celebrate America's birthday with the Boston Pops and its world-renowned fireworks. Conductor Keith Lockhart is featured along with guest artists Melissa Etheridge, Andy Grammer and Leslie Odom, Jr. Learn how fireworks and cannons are timed to the "1812 Overture" and mingle with event-goers from around the world.