The melody of Bang Bang Bang by Selena Gomez runs 408 notes across 45 bars, 2:41 long in Am at 114 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? Bang Bang Bang chords and lyrics.