The melody of When You Really Love Someone by Alicia Keys runs 629 notes across 77 bars, 6:08 long in Em at 68 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? When You Really Love Someone chords and lyrics.