What Now by Rihanna is in Am at 93 beats per minute and runs 3:52 across 43 bars. It uses 11 chords — Abm, Cb, Gb, Gbsus4, Fb, Ebm, Db, G, and a few more. 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? What Now guitar melody tab.