Chords for [MV] Mad Clown(매드클라운) & Kim Na Young(김나영) - Once Again(다시 너를) l Descendants of the Sun 태양의 후예 OST (). Spark is the smartest and most interesting app to learn and enjoy playing guitar. Spark is an all-around app for beginners and advanced players to learn any song with chords or master new skills with hundreds of lessons and games in Spark.