Sing by Pentatonix is in Abm at 160 beats per minute and runs 2:20 across 81 bars. It uses 21 chords — N.C., Ebm, Eb5, Db6/9, Cm7, Cb6, Bb, Bbsus, 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? Sing guitar melody tab.