To start learning Polyphia - Nightmare chords, centre your learning around these elemetal chords sequence: Em, G, Em, Bm, D, G, Bm, D and A. For a smooth transition, initiate your practice at 56 BPM and gradually match the song's pace of 113 BPM. With an eye on the song's key D Major, set the capo that best suits your vocal range.