When You Really Love Someone by Alicia Keys is in Em at 68 beats per minute and runs 6:08 across 77 bars. It uses 4 chords — Em, Am7, Bm7, B7. 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? When You Really Love Someone guitar melody tab.