"It's My Party" is a song by British singer-songwriter Jessie J, released as the second single from her second studio album, Alive (2013). The song was written by Jessie J, Claude Kelly, John Lardieri and Colin Norman, and produced by Lardieri and Kelly. The track premiered on UK radio on 5 August 2013 and was officially released in the UK via iTunes on 15 September 2013. Jessie J recorded the official video at the end of June and it was directed by Emil Nava.

"It's My Party" is a mid-tempo song in the key of A major, written by Jessie J, Claude Kelly John Lardieri & Colin Norman. The song received its first radio play on Capital FM on 5 August 2013 and was released on 15 September 2013. The song shares its title with Lesley Gore's 1963 hit song. Speaking on the syndicated radio show, In:Demand with Alex James, Jessie revealed that it was her detractors who inspired the song. "A lot of the time the haters - I hate calling them haters but that's the easiest way to sum it up - they need love more so than anyone else," she said. "I don't think hate does anything for the world. It doesn't do any good. I wanted to make sure I had a song that represented what I'm about."

"It's My Party" garnered mixed reviews from critics. UnrealityTV gave It's My Party three stars (out of five) wrote, "I feel Jessie’s vocals are distorted at times on It’s My Party, the chord is too high – it was the same problem with Wild at points in the song". Kevipod of DirectLyrics said, "On the first listen, "It's My Party" sounds like a big utter mess. It strikes as generic, not current, the vocals are a mess, and the talking she does is...I cannot find the right words to describe this. What's happening to Jessie J this era?. For real!".

Karen Lanza of PopCrush commented: "Hearing a song called ‘It’s My Party,’ you expect to indulge the recording artist as much as you do your bestie when she throws herself a birthday bash. It is, after all, her party, and she’ll most likely do whatever the heck she wants. But it doesn’t mean you have to like it. With her newly released single, Jessie J fails to take full advantage of the listener’s goodwill following the urban-edged ‘Wild,’ the well-received first track off of her as-yet-untitled second album. With its frantic beats and eff-off lyrics, ‘It’s My Party’ aims to be a full-stop dance-floor anthem for the waning days of summer. The lyrics are indeed fun — who doesn’t love telling off haters? — but the tune itself is lacking the hooks to keep you from forgetting it the second its 3 minutes, 38 seconds are over".

...
Wikipedia