Songfacts®:

• The That's The Spirit album title is taken from one of this song's lyrics. Frontman Oli Sykes explained to Kerrang!: "The phrase 'that's the spirit' came to when I heard it being used and I thought about how ironically bleak the sentiment is. It's only ever really used by people when there's no answer or no solution - just get on with it. That's what 'Happy Song' is all about - it's a sarcastic way of making light of a sh---y situation."
  
  "We all live with depression to some extent - I'm pretty confident in saying that. We all have problems that we need to address, but we ignore them. The way I see it is, if we don't laugh, we'll cry, so let's poke some fun at the fact that we're all f--ked."
• For their songwriting, BMTH often mix two different sounds that they'd heard, combining elements. Keyboardist Jordan Fish told HMV.com: "For 'Happy Song,' Oli wanted to do a song with cheerleaders that sounded really upbeat and happy, but is actually really miserable, the song developed from there."
• Oli Sykes (from Billboard magazine): "'Happy Song' is a sarcastic open letter to the world about how we use superficial and trivial things to ignore the real problems."
• The cheerleading part of the song was recorded at Oli Sykes' Drop Dead clothing store in Sheffield. Jordan Fish told Kerrang: "The voices you here are all friends of ours, plus some family of the band, basically we all got together on the gang vocals, and I asked all of the girls to do it in their most American voices, you know, Super happy."