Why wait for a broadcast on your local public TV station when you can catch The Boston Pops any time online? Web broadcasts come complete with commentary to guide you through the music: The secondary theme suggests a bustling Arabian marketplace. You can turn the commentary off if you prefer. Interviews and behind the scenes glimpses are offered. Also revealed is a charming gap between conductor Keith Lockhart’s front teeth airbrushed out of his smiling portraits. Ah, TV.