“American Masters” (8 p.m., PBS): The latest installment of “American

“American Masters” (8 p.m., PBS): The latest installment of “American Masters” goes behind the scenes of the popular radio show, “A Prairie Home Companion,” and inside the imagination of Garrison Keillor, the funny man who created it.

“Monsters Inside Me” (9 p.m., Animal Planet): “Monsters Inside Me” sounds like a gruesome horror flick. Instead, it’s a new series that focuses on real-life microscopic organisms that can wreak silent havoc in human bodies.