<Tr> <Td> ← Previous "This is How We Do It" </Td> <Td> Next → "It's a Long Way Back" </Td> </Tr> <Tr> <Td_colspan="2"> List of Grey's Anatomy episodes </Td> </Tr> <P> "Song Beneath the Song" also known as Grey's Anatomy: The Music Event, is the eighteenth episode of the seventh season of the American television medical drama Grey's Anatomy, and the one - hundred forty - fourth episode overall . It was named after a song by American singer Maria Taylor . Written by series creator Shonda Rhimes and directed by Tony Phelan, it premiered on ABC in the United States on March 31, 2011 . It is the series's first musical episode, and features the cast performing songs previously featured within the program . It is accompanied by a soundtrack album, titled Grey's Anatomy: The Music Event, also released on March 31, 2011 . </P> <P> The episode revolves around Callie Torres (Sara Ramirez) and Arizona Robbins (Jessica Capshaw), just after they are involved in a vehicular collision . Various songs are performed by the cast members, as they attempt to save the life of Torres . Rhimes originally idealized the episode at the conception of the drama, while the show remained untitled . The episode opened to mixed reviews from television critics, and it was the second most watched program of the night . "Song Beneath the Song" was ranked in several "best and worst" lists, and the soundtrack was included on the Billboard 200 . </P>

What episode is the musical in grey's anatomy