He's an O'Neill drama, he's Whistler's mama, he's Camembert. Who's? Ronald Reagan, that's who's. The president is sung several peppy choruses of Cole Porter's "You're the Top" as the finale to a swellegant, elegant "In Performance at the White House" tribute to Porter at 9 tonight on Channel 26.

Nancy Reagan, once more the lady in red, sings the three-word title, and members of the cast fill in the rest of the lyrics near the end of the one-hour special, third in the PBS series of salutes to American popular composers (following the Gershwins and Rodgers and Hart). Times being tough all over, but particularly at the White House, the president undoubtedly will accept choruses of "You're the Top" from whatever sources he can get them.

The concert, taped June 28 in the East Room, stars Marvin Hamlisch, Mel Torme', Kaye Ballard, Patti Austin and June Allyson, who tells an anecdote about Porter hiring her for the chorus of "Panama Hattie" and then puts on this enormous pair of glasses so she can read "It's De-Lovely" off the cue cards. She's the dear little thing she always was.

Executive Producer John Musilli made this a neat, polite, conservative tribute to Porter, with no freshly salvaged treasures except for the relatively rare "Tale of an Oyster," which Ballard sings with undue muggery. In his nightclub appearances, Bobby Short does a much better job with this number. But then Bobby Short does much better jobs with most numbers.

Since this is a tribute to a man renowned for his glibly witty lyrics, Torme''s indulgence in scat seems a trifle misplaced during his selections, and he ruins the punch line to "Miss Otis Regrets" by mis-phrasing it (and what a molding chestnut that ditty is, anyway). But Torme' is in tip-top form dueting with Austin on a three-song medley and on the inevitable "Night and Day."

Austin's the most pleasant surprise of the night; her voice is warm and full-bodied, and her "In the Still of the Night" gives it haunting new life. In "From This Moment On," she sings Porter's dictum "No more blue songs, only hoop-dee-doo songs," and this, by and large, sets the mood for the evening, though the hoop-dee-doo does give way to the occasional patch of blue.

While "You're the Top" is clearly sung to the president, there's no attempt to make other lyrics relevant. If there were, then a line from "Begin the Beguine" might be thought of as a short history of the Reagan Era: "What moment divine, what rapture serene; 'til clouds came along to disperse the joys we had tasted ..."

Or one could imagine Porter referring either to the Reagan administration or to the Iran-contra scandal as having been "a trip to the moon on gossamer wings ... just one of those things." Unfortunately, no one sings to the assembled glittery Washington crowd the verse from Porter's "Blow, Gabriel, Blow": "Come on you sinners, get up you sinners, you're all too full of expensive dinners."

Perhaps it's just as well.

In his closing remarks, the president recalls that Porter, born into wealth and celebrated for his sophistication, spent much of his life in pain, the result of a fall from a horse. Though taped well before the riding accident that took the life of Commerce Secretary Malcolm Baldrige last Saturday, the story is eerily similar. Baldrige was not among those in the audience for the Porter program.

David Deutsch, the director, imposed a polished, decorous intimacy. Deutsch outdid himself this year with his direction of the July 4th National Symphony concert from the Mall. It was so much more imaginatively done than the Boston Pops concert that followed it, a big feather for the not overcrowded cap of WETA. The Porter show is, of course, a less kinetic occurrence -- but, in its way, also an invigorating one.

For a White House musicale, the mood is enticingly sprightly. The surprise omission is Porter's ballad "True Love," since that's the name of the canoe in which the Reagans paddle about at their Santa Barbara ranch. But maybe it was thought that would be a bit much. As it is, the Porter tribute is just much enough. It's an old Dutch Master, it's Lady Astor, it's ... er ... Bloomingdale's!