You can bet that the line, "William Parker, baritone," will appear on the brochure of the Washington Performing Arts Society next season. Parker recently won the Kennedy Center-Rockefeller Foundation Competition for Excellence in the Performance of American Music, which this year was open to singers.

A part of his prize -- in addition to $10,000 cash and a recording contract -- is a guaranteed concert tour for the coming year. It will be good to have a man singing a song recital for the WPAS. This year Victoria de los Angles, Teresa Berganza, Janet Baker, Shirley Verrett, Marilyn Horne and Galina Vishnevskaya are doing the honors, and there will be very little American music in those recitals.

From the evidence of last week's grueling contest, Parker is an excellent prospect for an successful tour as a song recitalist. In both the semifinals up in the Kennedy Center's Terrace Theater and in the finals in the Concert Hall, his enunciation in English, German, French and -- as far as I could tell -- in Hungarian, was not only crystal-clear, but projected with great feeling for the inner meanings of the words.

This gift, among the obvious others, is a necessity if the art of the song recital is to be restored to its onetime rank as the most popular form of concert. These days, thanks to microphones and recordings, we have become accustomed to hearing words clearly. It is up to our best singers to see to it that we hear their words just as clearly.

Let me cite a couple of examples. An American baritone, who speaks perfectly clearly, got up in the semifinals and sang Charles Ives' lovely song "Grantchester," which he pronounced as if it were spelled "Grahn -chester," Can't you just imagine what Charles Ives -- who used to shout, "What the hell has sound to do with music!" -- would have said if he had heard that prissy-elegant pronunciation. What's the matter with singing it so that you hear "Grant," as in Ulysses Simpson Grant, rhyming with "ant," followed by "chester." It's very simple. Unless, that is, you are a teacher of voice and think that the pearly -shaped tone must never be interrupted by anything so vulgar as a consonant!

Parker's words were always clear, and so were those sung by the youngest competitor, baritone Sanford Sylvan from Boston. This amazing artist is not yet ready to be heard in our larger halls. But what recitals he could sing, for the series at NIH or the Jewish Community Series or the University of Maryland Community concerts. The third-prize winner last week, Sylvan -- who has, after all, sung with the New York Philarmonic -- sang circles around the No. 2 man.

This is not overstating the case of the texts. No pianist or violinist would be tolerated if he or she got up on the stage and skipped over as many essentials as are passed over by these singers who give you "ahin" instead of "dahin" or pass lightly and smoothly over Whitman's lines, "so that his brains partially exuded!"

To be fair, the Concert Hall's acoustics tend to swallow words. But the Terrace Theater, while its dryness does not give an ounce of reverberation or vitality to the singer's voice, does transmit with perfect fidelity every sound and syllable produced by the vocalist.

There is, of course, more to the song recital than mere words. The judges were told that "program effectiveness is an important criterion. The winners will be judged on performance ability and effectiveness of program."

If there were one criticism of the repertoire suggested for this competition, to which the singers were allowed to add anything else they chose, it would be that it failed to mention what you could call the romantic ballad, or the socko song with which great song recitalists in the past used to send their listeners right into orbit.

Marian Anderson rarely sang a recital without tossing in "Will-o -the-Wisp," in which her wit reduced her audiences to helpless whoops of laughter, or "Comin' Through the Rye," which she made a thing of imcomparable glory. And who would forget Gladys Swarthout singing "Ah, Love, but a Day," by Amy Beach. Or Rise Stevens, or Rosa Ponselle, for that matter, singing "Homing," or John Charles Thomas knocking 'em dead with "I Love Life."

Things were too serious, too intellectual, almost every minute of the time in these sessions. It was just the way Vladimir Horowitz describes today's piano recitals: "One sonata followed by another sonata followed by another sonata. There is no time for the short, brilliant piece, or the light, graceful touch."

What should be instituted in Washington immediately is a song recital series. There have been peano series here for years, as (for more years) there have been in Chicago. The song recital is due for a big revival. Donald Collup, two weeks ago in the Phillips Collection, showed himself on the threshhold of what ought to be a fine career in songs; Sanford Sylvan last week in the Kennedy Center is as close to the same goal, which is the goal William Parker has made clear is his birthright, if one of which he has worked long and hard.

Radio programs of songs -- classical, romantic and sentimental -- bring in substantial amounts of favorable mail, especially from college students who say, "Don't think we are not interested in sentiment, too!" The right singers of the right songs can restore a marvelous fragrance to our concert halls, and one you can't sniff anywhere else.