If you haven't already by now, I encourage people to check out Joss Whedon's web-musical hit,
Dr. Horrible's Sing-Along Blog. I initially avoided it, but I've since checked it out and enjoy the quirkiness and dark theme of the show. Whedon is somewhat of an amateur composer, but there are some great songs in this that have a
Sweeney Todd/ Jekyll & Hyde feel about them. His other well known 'musical' is
Once More With Feeling - Buffy, The Musical. He's the writer/director of TV shows like:
Buffy The Vampire Slayer, Angel, Firefly, and Dollhouse (all cult hits). Similar to Frank Wildhorn, most people either love or hate Whedon's work.
U.S. citizens can watch Dr. Horrible here:
http://www.hulu.com/watch/28343/dr-horribles-sing-along-blog (I don't think it will work for people out of the country)
