Chords for 30 Seconds to Mars - City of Angels / Acoustic @ NRK P3 (). 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.Spark Chords|30 Seconds to Mars - City of Angels / Acoustic @ NRK P3