In preparation for the Cecilia Chorus of New York's premiere in the USA of The Prison by Ethel Smyth, I have produced full audio-realisation, with individual rehearsal lines for double Soprano, Contralto, Tenor and Bass. It is a task that requires great care for more than 1000 bars of music and a running time of about 50 minutes. But the end result is that a work that has been very seldom heard can become familiar to choir members and their own practice can be done in the context of the work at large.