IT'S FRIDAY night at the Towson Family YMCA and one of the more popular classes there is in session. Along one wall of the room is a line of about 20 men, and along the opposite wall a like number of women. In the middle instructor Lois Finifter calls out an order to her students:
''Ladies back on the right foot; gentlemen forward on the left. Ready? And a 1-2-3, 1-2-3, 1-2-3, 1-2-3.''
The course is ballroom dancing and the dance is the waltz -- as traditional as they come. Before the four weeks of 1 1/2 -hour classes are over, Finifter's students also will have learned the foxtrot, cha-cha, jitterbug, rumba and tango.
This is a class for beginners. Finifter makes it clear that she's not priming people for competitive ballroom dancing.
''Basically, people want to be Mr. and Mrs. Jones on the dance floor,'' she says. ''They don't want to fling their partners overhead; they just want a little confidence. They're learning social dancing so they can go out and have a good time.''
Meanwhile, they're having a pretty good time inside the classroom. The 40-some students enrolled in this first fall session watch closely as Finifter demonstrates a basic box step -- first to the men, then to the women. After a bit of practice individually, they pair off to test their skills as couples.
If there's an extra person in the group-- yes, some people do sign up for the course without a partner -- the instructor will dance with him or her for a while. (''I don't want anyone to feel left out,'' she says.)
This ballroom dancing class is typically diverse, says Finifter. Students arrive in everything from dress suits to sweat suits. Their ages and reasons for being there are just as varied.
Barry Johnson and Catherine Miller, both 25, signed up because they're getting married in December. ''We're having a formal wedding, and I think it would be nice to be able to dance with some of the older people there,'' Johnson says. Of course it wouldn't hurt if they could dance with one another, either.
They're taking the class with another engaged couple -- Jay Baumohl and Diana Wong, both 23. The younger pair won't be married until May, but they figure they've got enough occasions on their social calendar, including the Johnson-Miller wedding, to keep in practice until then.
Indeed, weddings seem to be a great impetus for taking dancing lessons these days. But they're not the only reason.
Take Richard and Catherine Cassedy, a 60-ish couple from Dundalk, for instance. They rarely went dancing in their 34 years of marriage -- ''I was always kind of shy,'' says Mr. Cassedy. But then they discovered Finifter's class.
''We love it. This is our fourth or fifth time here,'' says Mrs. Cassedy.
''Some people come in with more natural ability than others,'' Finifter says, ''but everybody learns something. And it's amazing how much you can get done in six hours.''
Actually, it is rather amazing to watch Finifter work the room. Shorter in stature than most of her students -- she's 5 feet 1 -- she's enviably light on her feet. She's commanding, yet sympathetic, as she coaches the pairs into mastering the sometimes complicated steps of a cross-over in a waltz or an arching turn in the jitterbug.
She'll scurry around the room to various couples, nudging a hand higher here or an arm lower there, all the while counting out the rhythm .
''Let the position be natural,'' she advises. ''If you feel twisted like a pretzel, it's wrong.'' Occasionally, she'll break in on a couple to dance briefly with the partner having a little trouble.
''Gentlemen, use your hands to lead. Use your arms. Dancing is a gentle motion.''
A full-time office manager by day, Finifter, 37, has spent her evenings teaching ballroom dancing for nearly 16 years.
As a child she learned ballet and modern dance at the Peabody Institute. Later, she studied ballroom dancing with her father, the late Milton Smith, who was a professional dancer on Broadway.
There was a time when Finifter would teach every night of the week at one community center or another in the Baltimore area. Now married and the mother of two young children, she's cut back her teaching to a single course at the Towson Y.
A little more than 20 couples signed up for her first class this fall, but Finifter says she has had as many as 35 couples in a single class in the past year. A new class is held at the Towson Y every other month from September through May. (The next one, to be held at 8 p.m. Fridays, starts Nov. 9.)
Finifter's not sure whether the popularity of ballroom dancing lessons indicates a resurgence of social dancing in general or not? Many of her students, she says, don't really care whether they ''use'' the lessons anywhere else or not. Attending class as an enjoyable, social outing is often an end in itself.
''I think they come because it's something they can do together,'' she says. ''And it's not like getting out on the racquetball court, where one person is going to beat the other.