I just listened to David Og play this on YouTube. http://www.youtube.com/watch?v=oiIkRz_aP8M&feature=related

I'm sure this is what everyone is talking about. The song is sung with a strong background beat, but I wouldn't call it 'upbeat'. I think the intent is to bring out the protest aspect of the song. Trevelyan was responsible for the genocide of 1,300,000 men women and children during the Irish famine.