Theatres are very much the same in London as anywhere else; the chief theatres, music halls and cinemas are in the West End. If you are staying in London for a few days, you'll have no difficulty whatsoever in finding somewhere to spend an enjoyable evening. You'll find opera, ballet, comedy, drama, revue, musical comedy and variety. Films are shown in the cinemas most of the day.
The best seats in theatres are those in the stalls, the circle and the upper circle. Then comes the pit, and the last of all the gallery where the seats are cheapest. Boxes, of course, are the most expensive. Most theatres and music halls have good orchestras with popular conductors.
You ought to make a point of going to the opera at least once during the season if you can. There you can get the best of everything - an exellent orchestras, famous conductors, celebated singers and well dressed audience. But, of course, if you are not fond of music and singing, won't interest you.
At the West End theatres you can see most of the famous English actors and actresses. As a rule, the plays are magnificently staged - costumes, dresses, scenery, everything being done of the most lavish scale. Choose a good play, and you'll enjoy yourself thoroughly from the moment the curtain goes up to the end of the last act. Get your seats beforehand, either at the box-office of theatre itself or at one of the agencies. When you go to a theatre, you'll probably want to seat as near to the stage as possible. But if you are at the cinema, you may prefer to seat some distance from the screen. In fact, I would say, the further away the better.