The dance and the music
Every dancer needs to understand the structure of the dance and its relationship to the music, so this isn't really a special requirement for a caller. However you do need a much deeper understanding if you are to make a success of calling. You haven't a hope of calling a dance well if you don't know how many steps it takes to complete a right-hand star.
Most dance tunes are in 8-bar phrases of duple-time music (two beats to the bar), often subdivided into two four-bar phrases. A very common structure for a longways dance is an 8-bar phrase repeated (customarily denoted A1 and A2) followed by a different 8-bar phrase, also repeated (B1 and B2). Each of these 8-bar sections will correspond to 16 steps of the dance, so that a complete turn of the dance takes up 64 steps. However there are many variations on this, especially in modern dances, where anything can happen. In particular, phrases may comprise 10 or 12 bars, or the dance may take up 5, 6 or 8 phrases instead of 4. In some dances, the music is in triple time, so that there are three beats to the bar, and the phrases are then usually 4 bars long, or 12 steps. If you're familiar with musical notation, this will be evident as soon as you listen to the music. If the ideas are unfamiliar to you, then you need to get to grips with them before you should even think about calling. In any case it's helpful to listen to some music tracks for familiar dances, count the beats, and work out how the movements fit the music.
Calling for the first time
When you start, don't try to take on a whole evening's dances at one go. If you dance regularly with a club, whether you have a regular caller or a rotation system whereby people take turns to call for an evening or half an evening, you should be able to arrange to call just one or two dances at first, until you gain confidence. You can add to your repertoire gradually until you have enough dances to last for half the evening or longer.
Those first one or two dances should be ones that you know by heart. You will want a crib of some sort; most people use file cards, one for each dance. But the crib is just to give you confidence that if your mind goes blank you won't be completely lost. You should aim to call the walkthrough and the dance without it. You can refresh your memory from the crib before you start, but ideally you shouldn't even need that. Don't try to do anything elaborate at first; choose dances that will be fairly familiar. If there are likely to be novice dancers, go for something very simple indeed. The experienced dancers won't mind — they certainly won't if they've ever called themselves. Bearing in mind the over-riding objective of helping people to enjoy their dancing, however, try to choose dances that are simple but enjoyable and avoid the ones that are simple and boring. Views will differ on this, of course; I would put Juice of Barley in the first group and Rufty Tufty in the second.
Having announced the dance, your first task is to get the sets made up so that everyone who wants to dance can do so and anyone who doesn't want to dance can sit out. This isn't always possible, and then you may need to cajole the reluctant dancers to join in to make up numbers. If you begin with a longways dance this will be much less of a problem, but in that case you may have to decide whether to have one set or two, or perhaps whether to arrange the sets along the room or across it. The conventions in your club will decide most such matters, but if there's a decision to be made, you are the one who makes it. You may need to over-rule people who think otherwise, or perhaps give in gracefully if you find that the general view is against you.
You may also want to suggest a reallocation of partners or couples. Don't let the beginners gravitate to the bottom and dance with each other all evening; they won't learn the dances, they won't have any fun, and they won't come back next week. If you encourage the beginner couples to split up, and the experts to dance with them, they will learn much faster and may well enjoy their dancing from the start.
Walking the dance through
Here, as with calling generally, you need to be in sympathy with the dancers. If everyone knows the dance, you may not need to walk it at all, but just give a brief reminder. The more beginners you have, and the less familiar the dance, the more time you'll need to spend on the walk-through. This is one of the hardest things to get right. Spend too much time on the walk-through and you bore everyone rigid; spend too little time and the dance will fall apart. When there are beginners about you also have to decide whether to explain how to set and turn single, or whether you can leave that sort of thing to the other dancers. Some such things are more important than others: a set and turn single leaves everyone in the same place, so it isn't critical if a beginner doesn't know what to do, but a beginner who turns the wrong way in a circular hey (as many do) will cause chaos.
Calling the dance itself
This is where it's vital that you know the dance by heart, because your eyes should be on the dancers, not on your crib. The trick is to give just the right amount of information at just the right time. The right time is before the movement starts, so that the dancers aren't left adrift, wondering what to do next. How much before is a matter of judgment; it's one of the things that distinguishes a good caller from a bad one. The amount of information too is a matter of judgement; obviously you'll need to call more for beginners or for complicated dances. But if you've explained the dance clearly enough, you should be able to cut down the calls after the first turn or two, and leave the dancers to get on with it. But that doesn't mean you can take your eyes off them; you must be ready to start calling again at any moment if you see that anybody is coming unstuck, or if you see anyone with that worried look that says 'what do I do now?'
Once you've called a few dances, you'll begin to understand the pitfalls. A good way to improve your technique is to observe other callers critically, to analyse where they go wrong and what they get right, to ask yourself whether you make the same mistakes, and try to modify your own calling accordingly.
Some practical details
If you call from records or tapes, do you understand exactly how the record player or tape recorder works? How loud does it have to be? If there's a microphone, do you know how to use it? Most microphones have to be held in a very specific position, close to your mouth and at the right angle. If there's no microphone, you'll have to speak up to be heard at the other end of the hall, over the music. Ask a friend to tell you if you're getting it right or not.
The male chauvinist caller
Are you addressing your instructions just to the men ('put your partner on your right', for example)? Some consider that this is legitimate, since traditionally the man has the responsibility for leading his partner through the dance, but many women nowadays favour a more equal approach. Since it's usually possible to avoid offence by using only a slightly different turn of phrase ('stand with the woman on the right', for instance) why not make that a habit?
Consider too what terms you use for the sexes. 'Man' is brief and 'gentleman' is unnecessary, so that's no problem. For the females, 'girl' was once common but is now taboo. 'Woman' is the preferred term in Playford and is the politically correct usage, but some prefer 'lady', especially in the American context. There is no absolute rule, but you should give the matter a bit of thought.
Planning a programme
When you get to the stage of planning a whole evening's dances, you must still choose dances that you know well enough to call without a crib, but now you must put together a range of dances, varying in style, formation and difficulty, so that you have something to please both the beginners and the experts. Inevitably some of these will be more difficult to call, but by now you should have enough confidence to cope with that. Moreover you have to be prepared to vary your programme as you go along. If you'd planned to call Levi Jackson's Rag but you have 18 dancers, eight of them would have to sit out. Substitute a 3-couple dance or a square; perhaps another couple will turn up to let you do Levi Jackson later. Make sure that the substitutions don't spoil the variety of your programme; for instance, Heswall & West Kirby Jubilee would be a good substitute for Levi Jackson if you're a few dancers short, because it's similar in style but needs only four couples instead of five. (It is more difficult to call, though.) Similarly you may have to change the program if the dancers turn out to be more or less competent than you expected. This is less likely to be a problem if you know the people — if it's a club you regularly dance with yourself, for instance — but even then a bunch of beginners can turn up and cause mayhem if you don't make allowances for them.
Calling unfamiliar dances
Until you've gained a good deal of experience, you shouldn't attempt to call any dance that you haven't danced yourself. Eventually, though, you will want to call dances that you know only from a recording. This requires work beforehand. You must still learn the dance by heart; but now you must try to foresee the problems that the notation doesn't tell you about. There is no substitute for working through the dance in detail, so that you know just how the dance fits to the music, and so that you can see any ambiguities in the notation and work out how the dance is supposed to go. If you can dance it, on your own or with a partner, so much the better; it is easier then to see just how much music you need for each movement, where people have to move quickly and where they can take their time, where there are awkward turns or changes of direction, and so on. If you're a man, try to visualise this from the woman's point of view too; if you're a woman, you're probably used to dancing as a man, so this should be easier for you.
Another thing you may want to do is to call a dance for which you have no music — perhaps you danced it last Saturday, and made notes of the figures, but don't have it on record. Usually it's possible to find alternative music in the club's collection, or in your own, but be careful that it really does fit the dance, not only in terms of length, but in terms of detailed structure. The tempo needs to be right, too. Beware of calling a familiar dance to the wrong music; maybe there's a track on your new CD that you're dying to use for a dance, but if you use it for a dance that has its own tune, you'll annoy everyone who knows the usual tune, and if it doesn't work as well as you thought it would you'll annoy everyone else as well.