Today in 1868, at least on paper, Scott Joplin was born, though his actual birth date is probably a different day. He's best known for his groundbreaking ragtime works like "Maple Leaf Rag" and "The Entertainer," but Joplin also wrote two operas. Plus: today in 2013, musician Dave Mustaine of Megadeth composed an unforgettable tweet about a "cool building" in Wisconsin.