The ban played on

Memo to: Secretary James G. Watt Re: Rock and the ''right element'' From: Music Director, Department of the Interior

We were sorry, Mr. Secretary, to hear the epic outcry that arose when you decided the Beach Boys ought not to sing at the 4th of July celebration on the Mall because they might attract the ''wrong element.''

Knowing our chief, we trust you were not intimidated by that disc jockey at WASY who locked himself in and threatened to play nothing but Beach Boy records. By the time you read these words, all that will be forgotten - well, almost forgotten - and the plaster foot the President gave you will be collecting dust in your trophy room.

But before the Beach Boys contretemps becomes history, we respectfully suggest you consult our little department when you make your next foray into music criticism, a field more dangerous than politics by far.

For instance, our files would have told you that George Bush had employed the Beach Boys in his 1980 campaign. You could have anticipated that devastating announcement from his office: ''The vice-president thinks highly of the Beach Boys.''

We would have informed you, furthermore, that the Beach Boys are Californian right down to their surfboards, which they sang about in their first hit more than 20 years ago. Californian, Mr. Secretary. You understand what that means?

Our music resources library, which includes ''The Rolling Stone Illustrated History of Rock & Roll,'' would have reported that, far from representing the ''wrong element,'' the Beach Boys are considered ''clean, somehow safe'' - a family operation.

Worst of all, they have composed songs in praise of conservation.

The President may even have visited the Radiant Radish, the organic foods store established by one of the Beach Boys in Hollywood. Our files are incomplete on this point.

We certainly could have told you that musicians, unlike redwood trees, talk back. It will now have to go into our files that the Beach Boys defended their ''wholesome'' reputation and called your criticism of them ''ludicrous.''

The FBI could not build a case against John Lennon. What chance does a Secretary of the Interior have against the Beach Boys?

If you still think rock musicians are pushovers for a politician to take on, consider the eminence of Mick Jagger, who has just been given an advance of $3 million for his autobiography - more money than any English writer from Chaucer to Graham Greene has ever been paid for a single work.

What else have you learned? We assume you have discovered the limits of the fans of Wayne Newton.

You have learned, too, that when you worry out loud that the Beach Boys fans - being the ''wrong element'' - are going to scuff up the sod on the Mall, you expose yourself to two rebuttals:

1. Grass is not going to flourish under 400,000 pairs of feet, even if they belong to lovers of the Vienna Boys Choir.

2. The public does not like to think the department frets more about the ecological side effects on Mall grass than about strip-mining.

A final word of advice:

We are here to serve you, sir. But if you decline to clear your statements on music through our office, may we request that you exercise your refreshing frankness in other areas? Perhaps a flat-out attack on what the Washington Redskins and their ''wrong element'' do to the turf of a football field might give you the same bracing satisfaction of being absolutely alone?

You are an energetic man with many things to say on many subjects, from the Sierra Club to the American Indian. You have by no means exhausted the world's stockpile of plaster feet - a lower-extremity badge of one's independence. So, if the next plaster foot fits, wear it proudly, we say. Just don't tap it to music.