The stage will be built slightly raised for most theatres and each perfomramance will require a differnt set and special effects. The stage will normally have large supports above it and to each side to hold lights, speakers and wiring, because of the heat ommited by these they will often include fire-proof or safety curtains as well as the usual thick curtains behind them.
|Scene shot from The Lion King - eventim.co.uk|
Some example's of exceptions of this would be the London cast's perfomance of 'The Lion King', where they have their drummers in the balconies just above the sides of the stage, Chicago on Broadway where they had the band in the centre of the stage and We Will Rock You in The West End where the band was on a side balcony overlooking it, and one of the guitarist came down onto the stage for a song completely.
The Lion King's perfomance contained performers moving throughout the audienance and even moving from the upper floors to the stage spinning bird props above the audience's heads.
The stage will have any special effects done to it that is needed such as gutters for people to came out of or turntables etc.. many different sets will need different effects and so the way the stage is built will often become very specific to a particular show.
(Imelda Staunton (Mrs Lovett) and Michael Ball (Sweeney Todd) - telegraph.co.uk)
The other thing that is particular to a show is backdrops and set buildings. They can vary greatly from the bright, colourful land of Oz to the dark, deathly barber shop of Mr. Todd. Backdrops are an extremely important part of any show as it really sets the scene of each show... without it, audiences would not be able to completely understand the story properly. When making a set, the construction can be done throughout the world and more elaborate sets may need to be constructed separately in different places before coming to the final place to be put together. This creates employment on a world wide basis and different expertise can be found for their skills everywhere.