"We stand at a moment of becoming what we not quite are . . ." said Museum of American History director Roger Kennedy. "History records itself in the printed page and picture . . . and in the pitched human voice . . . a song in a picture-saturated time may be worth a thousand pictures."

All this was by was of introducing last night's Frank Nelson Doubleday lecture at the Smithsonian, the second in a series of four this year on American music. To illustrate and guide a look at the American musical theater, Kennedy called on Schuyler Chapin, former general manager of the Metro-politan Opera and now dean of the Columbia University School of Arts, and his son, Ted, erstwhile producer of the now-dormant Musical Theater Lab at the Kennedy Center.

For their black-tie, invitation-only audience of 600 in the Smithsonian's Flag Hall, the Chapins provided a troupe of five singers from New York to give expert testimony as to the vitality of musical theater. The performers, all unknowns, had a fairly heady audience for their one-night stand, with impresarios Roger Stevens of the Kennedy Center, Patrick Hayes of the Washington Performing Arts Society and Morris Tobin of the National Theatre joining such government types as Secretary of Defense Caspar Weinberger.

The Chapinsh talk was billed as "A View" and was intended, Schuyler Chapin said before the show, to remind the audience of the splendors of the American musical and urge them not to let it languish. Both Chapins said during their narration that the musical's state of health is not now very strong, but that they have hope. They believe that Stephen Sondheim is the only original talent around, but that he is perhaps living in the wrong era, because he has "no competition." By contrast; the recent hit "They're Playing Our Song" was characterized by Ted Chapin as "disgraceful," and "The Best Little Whorehouse in Texas" as a "hodgepodge . . . with an ugly set and a good title."

If the Chapins' narration lacked focus, the performers certainly did not, as each in turn showed that the best musical theater can move, excite, amuse or amaze as few other media can. Keith Rice showed off a beautiful voice in good old reliable "Oh What a Beautiful Morning" from "Oklahoma," and Maureen Silliman demonstrated the best result of the marriage between acting and singing in "Just a Housewife," a feisty lament from a failed musical called "Working."

The evening -- a one-time-only event, came complete with its own specially commissioned opening number, ("Someone's Donated Us to the Smithsonian"), and a smashing tapdance number by Randy Hugill, who also managed to stun the audience by singing after flinging himself around on the tiny square of dance platform. There was no finale, however, a major omission in an otherwise well-balanced evening.

"Music is emotional, words are rational," said Schuyler Chapin. "Blending the two together is the magic."