I've purchased the first act of Joss Whedon's "Dr. Horrible's Sing-Along Blog" starring Neil Patrick Harris, Nathan Fillion, and Felicia Day. It's about an aspiring super-villain, Dr. Horrible (Harris), his arch nemesis, Captain Hammer (Fillion), and their mutual fancy, Penny (Day). Dr. Horrible starts out the act answering emails from his ongoing blog, titled the same as the story. Then he breaks out in song. This is the same guy who created Buffy the Vampire Slayer, Angel, and one of my favorites of all time, Firefly. This is a musical. Check it out on iTunes if you can spare the $3.99 for all three acts. All of the actors do their own singing, I believe.