It’s My Party by Jessie J is in A at 128 beats per minute and runs 3:09 across 50 bars. It uses 9 chords — A, D5, A5, F#5, E5, C#5, E, D, and a few more. The chord diagram changes as the song plays and the words light up as they are sung, so you can strum and sing along without reading ahead.
Want the melody line note by note? It’s My Party guitar melody tab.