Jet Black Heart (Start Again) by 5 Seconds of Summer is in Bm at 80 beats per minute and runs 3:06 across 38 bars. It uses 8 chords — Bm, F#m, G, A, D, Bm7, N.C., Gmaj7. 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? Jet Black Heart (Start Again) guitar melody tab.