I might have an affinity towards tracks named "Birthday", but Katy Perry's version is my favorite track off her new album Prism. The song is bubbly like a glass of celebratory champagne and has an irresistible chorus. If there is anything Katy does well, it's making fluffy pop tunes.
This track stays in Katy's upper register, so it avoids any of her "Firework" over-singing. The lyrics are flirty: " Pop your confetti. We can get it on, so hot and heavy 'till dawn. I got you spinning like a disco ball. I'll have them playing your song."
"Birthday" is laid over a disco instrumental of jumpy guitars and grand brass. By the bridge, Katy lays the innuendos on pretty thick. Katy is one pop artist you never have to take to seriously (except when she wants you to on tracks like "Unconditionally" and "Love Me"), and that's what I love about her music.