on the book
On the Book was originally the person who followed the script and “prompted” the actors when they forgot their lines.
As theatre has become capable of more complex and elaborate technological feats, so the duties of the person On the Book have expanded, and now you can almost say that the person On the Book is the nerve centre of a performance.
During rehearsals, this person will record in the prompt copy of the script (or book), all the moves made, all the props used and so on. They’ll also take notes from the director, lighting designer, sound designer and so on about scene changes, lighting changes, and all other technical aspects of the show. Any changes made in rehearsal are then communicated round the company by rehearsal notes.
When the tabs fly out at the start of the show; when the lighting state changes; when there’s a sound effect – all these things happen because the person On the Book has cued them to. This means that you can have, say, the flash and the bang of an explosion, synchronised.
It also means that when things go wrong – for example, an actor forgetting their lines – there’s someone there to keep the lighting operator, sound operator and stage crew together, and tell them what to do next.
At the end of each performance, the person On the Book will write up notes about running times, the number in the audience, and anything that went wrong (although we all hope for a “clean” show, it doesn’t always happen). These show reports are used for wardrobe, workshop and so on to keep track of maintenance required, and for the theatre as an operational record.
(Prompting, the origin of this position, is now very rare in theatre. It is still common in the larger international opera companies, although prompting in this case is done by a member of the music staff – which must be a relief to the person on the book for an opera!)
