The best of Sheldon Cooper

It's an old song that I haven't heard in a long time but it's still very cute and it's 由 Katy Perry. =)

A song 由 Owl City. Meh, not my favourite song but I like it.

A sad song 由 Green 日 about how the lead singer, Billie-Joe Armstrong's dad died in a war.

Awesome song 由 Green Day.