can you please name the characters
Callie Torres, Arizona Robbins Mark Sloan
Song Beneath the Song
The episode revolves around Callie Torres (Sara Ramirez) and Arizona Robbins (Jessica Capshaw), 
grey's anatomy episode where callie is in car accident Song Beneath the Song is this is song? It is the eighteenth episode of the seventh season of the American television medical drama "Grey's Anatomy," when was it aired? March 31, 2011
wiki:5607241
Song Beneath the Song [SEP] Introduction
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 polarized 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 also charted on the "Billboard" 200.