To learn 王菲 - 約定 chords, your first step should be understanding these chords - B, C#m, A, F#m, B, A, B, E, B, G#m and C#m in sequence. Set your pace at 80 BPM initially and then sync up with the song's BPM of 160. Adapt the capo setting considering your vocal range, with reference to the key: E Major.
