Stage Management - Prompt Book
The Prompt Book is the master copy of the script or score, containing all the actor moves and technical cues, and is used by the deputy stage manager to run rehearsals and later, control the performance. It's sometimes known as the 'book', Prompt Copy or Prompt Script. The member of stage management (often the DSM) cueing the show is said to be 'On the Book'. (e.g. 'Clare's on the book for the next show').
As well as the script and/or score of the show, the prompt book also contains contact lists for all concerned with the production, information about the venue(s), show reports, local amenities, emergency procedures and any other information that may be needed during the run of the show. It's rightly known as the production 'bible'.
The book is usually laid out so that the script is on one side of a folder, and the cues are on the opposite side, with a line between the cue word / line, and the cue itself. Left-handed DSMs may prefer the cue page to be on the left of the folder. Most prefer it to be on the right, as below.
Example of cue layout for a play (other information that would be on this page omitted for clarity)
If professional practice is followed, the Prompt Book is used throughout the production / rehearsal process for the DSM / SM to keep notes of everything relevant to the show.
Some SMs like to use a column-based layout with the script on the left, and (for the right-handed) columns breaking up the right hand page, for notes about blocking, lighting, sound, props, set and followspot. (The columns used depend on the complexity of the show).
This type of layout means it's easy to see which notes relate to which tech department, and which can be ignored if you're calling cues. The notes should be written in pencil so that they can be erased & replaced with more detail as the production progresses.
Cueing for a Musical
For a musical, the DSM has a personal choice to either use the lyrics / libretto, or to use the full musical score. The decision depends on how complex the music is, and whether the lighting designer has cues that are on specific beats (rather than on specific words). An opera or operetta with very little spoken dialogue really must be cued from the full score.
Depending on copyright restrictions on the score, you could scan parts of the score and insert them into the script where needed (for example, the beginning and end of a song, as long as there are no cues within the song).
Another option is to insert dance counts into the script, to give you the correct beat for a cue.
For example, from Queen's Bohemian Rhapsody:
"Beelzebub has a devil put aside for meeee, for meeee, for mee" - 2 - 3 - 4 - 5 - LXQ49 GO
The following websites have useful resources about prompt books and stage management in general: