To learn Seongha Jeong - (Justin Bieber) Mistletoe - Sungha Jung chords, your practice should emphasize these chord progressions: A, D, A, E, F#m, E and D. You can use ChordU's Free Tempo controller to start at a slower pace and then gradually increase your speed. Align the capo with your vocal depth and chord choice, bearing in mind the song's original key: A Major.