Boyfriend by Justin Bieber is in Gb at 98 beats per minute and runs 2:31 across 39 bars. It uses 7 chords — N.C., Bbm, Ebm, Ab, Db, A5, Fm. 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? Boyfriend guitar melody tab.