How to Play "Fireflies" by Owl City on acoustic guitar

Aaron Gallagher teaches you how to play the song Fireflies. He starts off by telling the audience that if you have a standard tuning for your guitar you need to play your chords at a different place that he does. He has his capo on the 4th fret, but everyone else should have theirs on the 3rd fret. He found a chord online and felt that he could teach people how to play from that. He explains that the whole first verse is basically a G to E. He shows how to strum the guitar to create the right rhythm. As he sings and plays the song he tell you each time you change chords.