in the national theatre and broadway versions the music is performed by a 16-member onstage choir and a seven-piece chamber orchestra. in bristol the orchestra was expanded to 20 musicians and the choir was joined at the end of act 2 by a local chorus of 40 performers. the music includes parts or adaptations of handel's "messiah" and "theodora", as well as over an hour of original music consisting of songs, period-style dance, and chamber music, as well as dramatic underscoring.