Best Mistake by Ariana Grande is in Bm at 144 beats per minute and runs 2:53 across 61 bars. It uses 10 chords — Bm, Bb+, Am6, Gmaj7, F#sus, F#, F#+, Am, 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? Best Mistake guitar melody tab.