Let's see if you can figure it out if I give you a start.

Here's a site where you can hear it sung:

http://fiddlefreak.com/2009/03/20/the-unwanted-music-from-the-atlantic-fringe-mp3/

The first chord is Em, the second is D. Sound out the rest of it, which is probably in G (Em) and if it's not a good key, come back and ask about the wheel which changes chords for you when the key changes.

Now I'm off to a meeting.
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IMHO, that's not a good tune for such a happy song. It sounds like a tune about a battle.