Moving on to the next episode of the show, watch Grey’s Anatomy Season 7 Episode 18: Song Beneath the Song online to be aired on the 31st of March 2011. During this episode, a cataclysmic event rattles the doctors of Seattle Grace to the core, as Callie, on the verge of an enormous life-changing moment with Arizona, envisions her friends as it has never-been-seen before. The hospital drama will go somewhat musical and “Chasing Cars” (Snow Patrol), “How to Save a Life” (The Fray) and “The Story” (Brandi Carlile) are among the songs which the cast will perform.