If you'd like to hear a child shriek, change the Christmas angel at the top of the tree or set up the cre che in a different place, or decide that this year, instead of opening the gifts on Christmas Eve, they will be opened on Christmas Day.

Children are traditionalists and they don't have enough of a past to know that tradition is not always as solid as it seems. Life is full of shifts and shivers as one custom is set aside in favor of another, or a new layer is added on, until the period between Thanksgiving and New Year's becomes as encrusted with tradition as a boat with barnacles.

Thanksgiving is easiest, since most people concede the importance of The Turkey, even if family feuds often rage over whether the cranberries should be jellied or served whole, the sweet potatoes mashed or candied and the stuffing flavored with oysters or sausage or chestnuts.

But the traditions of Christmas are as varied as the nationalities that celebrate it. They are lumps in the melting pot, stubbornly refusing to blend. Turkey or roast beef with Yorkshire pudding, lutefish or Italian pasta? Most people solve the problem of conflicting customs by following all of them, until the Christmas season begins to resemble one endless party staggering its way toward year's end. We leave our shoes out on Dec. 6 to celebrate the feast of St. Nicholas (the Dutch way of distributing gifts), honor Sweden's St. Lucia on Dec. 13 with a festival of lights and a handful of saffron buns, have a Mexican posada lasting for nine days beginning Dec. 16, to re-create Mary and Joseph's search for an inn and celebrate their success in finding one by breaking a pin ata and passing out gifts.

There is that sugary, pastry Yule log from France, the buche de Noe l, which finishes off the Christmas meal; there is mistletoe wound into a kissing ball from England (courtesy of the Druids; the Christians also had the problem of opposing traditions and solved it by adding on). There is the Christmas tree from Germany, Advent wreaths with candles that must be lit each week, Christmas cookies to be baked, mincemeat pies and a Christmas pudding full of good luck charms, and, for heaven's sake, don't forget to decorate a suet tree for the birds. It's a wonder that anyone gets any work done during December.

Plopping down on top of all these national traditions, there are the family ones. "But we always had fill in the blank on Christmas Eve," screams the new husband. Or perhaps it is the Scotch pine versus the Douglas fir, or a sophisticated cocktail party to honor friends instead of the cozy carol sing around the fireplace.

Sometimes the pod is broken, forcing a change in traditions -- the first Christmas after a divorce, the first Christmas in a new town or in a new house. Sometimes what was once a good idea degenerates into a very silly one. The couple who always gave a black-tie dinner on New Year's Eve continued the tradition when they left Georgetown and moved to the country. Their friends drove over snowy roads, the women shivering in slinky sandals and bareback evening dresses to join them in a chorus of Auld Lang Syne. The couple finally called a halt to what had become a very inconvenient custom by giving a New Year's Day brunch instead. It was easier for their friends to find the farmhouse in the glittering light of a winter day, and no one had to tiptoe through the slush or shiver in the chill of a drafty house, with a de'colletage revealing more goosebumps than curves.

That couple was smart enough to know that no matter how silly a tradition, there is always someone enslaved by it. The year they made the change, they sent out the invitations to their New Year's Day brunch early in December, to let their friends know that they were no longer committed on New Year's Eve. When you break with tradition, you must announce the fact, so that the guests who have spent the last five Christmas Eves around your fire know that it is time to make new plans.

The first holiday when none of the children come home, or the year that a friend decides to go skiing in Aspen instead of holding the annual Christmas Eve open house, can be lonely for those left behind.

M.F.K. Fisher writes of a Christmas spent with her two young daughters in France. Their family had been split, and she was afraid that if they added themselves onto another family, it would make them miss what was gone. Instead, on Christmas Eve day, she rented a hotel room in Marseilles and turned her daughters loose in the town to buy food, gifts and ornaments for a homemade Christmas tree. They had their holiday feast at the hotel, exciting and fun because there was nothing in it to make them miss the past.

Sometimes, when things can't be the way they were, it is better to jettison the old customs and adopt new ones. Instead of sitting and feeling sad about empty stockings dangling from the mantel, give a sophisticated Christmas Eve dinner for close friends -- champagne and caviar, pheasant or quail, or a very good burgundy and a venison stew. Do something that takes so much effort there's no time left to think of how it used to be. And if friends have closed down their hearth for the holidays, open yours.