To learn Joshua Aaron - Hoshiana chords, grasp the musical fabric of the song with this sequence - A, Abm, G, Gb, Bm, A, Abm, A and Bm of chords. A strategic approach would be to train at 80 BPM initially, and then accelerate to the song's tempo of 160. Considering your vocal pitch and chord choices, adjust the capo in accordance with the key: B Minor.
