Billie Eilish has joined the cast for a pair of forthcoming performances of The Nightmare Before Christmas, in which she’ll voice the character Sally.The shows, which will take place at Los Angeles’ Banc Of California Stadium on October 29 and 31, have been billed as “live-to-film” concert experiences, meaning the Disney film will be played on-screen with live musical accompaniment from an orchestra.Eilish will perform ‘Sally’s Song’ from the 1993 Tim Burton musical, with the film’s composer and