Thirty years ago the inimitable and, alas, irreplaceable Noel Coward came to the colonies with a one-man show. He took it to that citadel of urbanity, Las Vegas, where he startled the natives with a program of hilariously ribald songs. These included "A Bar on the Pic- cola Marina," about the unfortunate Mrs. Wentworth-Brewster's thirsty libido, and "Alice Is at It Again," about Alice, who was, well, at It again, but above all there was his own rendition of Cole Porter's "Let's Do It," which contained such lines as "Belgians and Greeks do it/ Nice young men who sell antiques do it" and "All famous writers in swarms do it/ Somerset and all the Maughams do it."

We were shocked. It was 1955; we had blushed enough already when Porter had told us in "Kiss Me Kate" that "in the dark they are all the same" and when Lorenz Hart in "Pal Joey" had permitted the observation by a cynical Broadway lady that "He's a laugh, but I love it/ Because the laugh's on me." These wittily risque' lyrics were very much exceptions to the rule of the day; when we sang of love three decades ago we were far more likely to ac-cent-tchu-ate the positive, to sing of June and moon and spoon, than to murmur, even by indirection, of things that went on between the sheets. Small wonder Coward's tunes seemed so daring.

So what are we, we who cut our eyeteeth on Georgia Gibbs and Tony Martin and Gogi Grant and Eddie Fisher, to make of the lyrics that have now aroused the indignation of the Parents Music Resource Center and the National Conference of Parents and Teachers? How are those of us who went about sobbing "my heart cries for you, sighs for you, dies for you" to come to grips with lyrics that deal in the most specific terms with violence, occultism, drugs and, of course, sex in all its conventional and kinky manifestations? How are we to deal even with a song so relatively tame by today's standards as Bruce Springsteen's "I'm on Fire," for which in 1955 we would have had our mouths washed out with soap?

Probably we aren't going to deal at all, for this is a whole new world. The parents and teachers are right to be angry about the scabrous lyrics to which children can now be exposed, but even if they manage to get "Parental Guidance: Explicit Lyrics" stamped on every record by Prince or the Sex Pistols, they are not likely to reverse the tide. One of the saddest but most pervasive legacies of the '60s, when we let it all hang out, is that there is no longer any clear distinction between the adult and the juvenile in the murky realms of sex, profanity and worldliness; we adults may know more than the kids do for the simple reason that we're older, but by contrast with our own youthful innocence, today's juveniles are appallingly sophisticated.

No one is to blame for any of this except ourselves. We begin in our houses, into which the general coarsening of the American language long ago crept. We use language around kids that our own parents would not have employed, even in private, between themselves, it then being quaintly thought that certain words simply did not pass between man and woman. We do not blink when, listening to children at play, we hear dirty words of four and more letters used as routinely as anything in Dick or Jane's vocabulary. The language of the streets is now the language of the rec room, and we make no particular effort to object.

Of an evening, when we sit down with the kiddies for diversions brought to us by the wits of New York and Los Angeles, we giggle together over sitcoms that leer and peek and whistle about sexual business in ways that never would have been permitted in a "sex comedy" starring Doris Day and Rock Hudson. Earlier in the day, while we were off at work or preoccupied with household chores, those same kiddies came home from school and, milk and cookies in hand, gazed their way through soap operas not much less explicit than what was once shown in movies thought to be scandalously "blue."

As for the omnipresent advertising to which children are subjected, much of it is predicated on the assumption that they either have active sex lives or are hard at work thinking about them. It is no exaggeration to say that the notorious Brooke Shields blue jean advertisements, at which 1980s America glances with scarcely a moment's pause, would have been centerfold material for the stag magazines of the 1950s -- and would have been cause for a spanking had a nice boy been caught eyeballing them. The advertising on television, all of which is seen by children, routinely makes overt sexual pitches and frequently relies on sexual jokes to get its message across.

In this climate -- a climate, it must be emphasized, created entirely by adults -- the lyrics of Prince and other alleged musicians are not so much exceptions to the norm as exaggerations of it. To say this is not to excuse them, but to place them in context. It is all well and good to get exercised about pop paeans to masturbation and cocaine, but to direct one's energy and anger solely toward the purveyors of pop music is rather to miss the point. We're all doing It; the only difference is that Prince is doing It a little more explicitly, a little more offensively, and very much more on the public stage.

No doubt the clean-lyrics campaign now being undertaken by these parents and teachers groups is part of a general backlash against the new hedonism, and as such it is not unwelcome. But people need to understand that a revolution has occurred from which there is almost certainly no turning back. In the privacy of some households the old verities may still be observed, and some parents may actually bring off the admirable feat of raising their children as children rather than tiny adults, but in the society at large, "liberation" has already been accomplished.

We can't have it both ways; we can't excoriate Prince on the one hand and then snigger over "Three's Company" on the other, any more than we can deplore Madonna and then moon over "General Hospital." The real problem isn't with rock 'n' roll but with us. Lorenz Hart wrote, "Couldn't sleep, and wouldn't sleep/ Until I could sleep where I shouldn't sleep." That's where all of us are sleeping now.