The melody of Firework by Katy Perry runs 423 notes across 56 bars, 3:14 long in Db at 126 beats per minute. The tab sits low on the neck, mostly under the fourth fret, one note at a time — no chords to barre and no strumming pattern to keep up with. A piano backing track plays the chords and bass underneath, so the line you are learning sounds like the record even at half speed.
Prefer to strum and sing it instead? Firework chords and lyrics.