The melody of Who You Are by Jessie J runs 354 notes across 68 bars, 2:55 long in A at 130 beats per minute. The tab sits almost entirely in the first two frets, 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? Who You Are chords and lyrics.