18 by 5 Seconds of Summer is in D at 160 beats per minute and runs 2:56 across 71 bars. It uses 15 chords — N.C., A5, F#5, G5, C, G, D, Em, 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? 18 guitar melody tab.