(Easy Piano Personality). Easy piano arrangements to Perry's blockbuster release featuring: Birthday * By the Grace of God * Choose Your Battles * Dark Horse * Double Rainbow * Ghost * International Smile * It Takes Two * Legendary Lovers * Love Me * Roar * Spiritual * This Is How We Do * This Moment * Unconditionally * Walking on Air. | Katy Perry - Prism, Paperback | Indigo Chapters