Learn the triangle-shaped open D chord on Strings 4 3 2 1. In 4/4 time, strum the D chord or play an arpeggio. Learn to pick with downward and upward strokes. Learn to use alternate picking, when playing eighth notes. Guitar: Harmony acoustic with pickup. BOSS Katana 50 amp. D’Addario Strings. Pickboy 1 mm TF Signature.