The melody of S&m by Rihanna runs 505 notes across 97 bars, 3:18 long in Em at 127 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? S&m chords and lyrics.