The chief appeal of American vaudeville was that it had something for everybody. The same might be said of the exhibition “Vaudeville Nation,” which opened Wednesday at the New York Public Library for the Performing Arts.

Vaudeville in its heyday (from approximately 1880 to 1930), was American show business in its chrysalis stage. Before movies, radio, and television, people went to the theater, where they watched their favorite comedians, singers, dancers, circus acts, and “nuts” strut their stuff, live on stage. Performing and traveling in those days were synonymous – an amazingly crude setup by today’s high-speed standards.Yet every branch of our modern entertainment industry owes a great deal to this foundation. In 2005 we are in every sense a Vaudeville Nation.

The story of vaudeville is a complex one, and a curator has endless options to dissect it: by race, by class, as a business history, as an insight into our democracy, even as a purely aesthetic journey. The touchstone of the new exhibition appears to be the collection itself.

Happily, the collections at the Library for the Performing Arts are second to none in this regard, and if the exhibition lacks focus from the narra tive perspective, it is an absolute treat to look at. Four-color lithography came in at the same time as vaudeville, giving period sheet music, theater programs, and posters a rich beauty unique to those days. Among the exhibition’s many treasures are examples of personalized business cards and stationary of vaudeville acts such as Harry and Eva Puck and “Sherlock Holmes,” a trained dog said to be able to read minds.

Examples of correspondence between vaudeville managers and performers illuminate the business side. Photographs of such key vaudevillians as Gertrude Hoffman, Eddie Foy, and Eva Tanguay abound, as do fliers, handbills, joke books, and pictures of the interiors of important vaudeville theaters like the Palace – one of the few of the old houses still standing. A happy surprise is a display of song slides: beautiful handtinted projections that appeared behind a singer to illustrate the content of the song (the patriotism of the era is evidenced by the many flags, eagles, and “Columbias” on view here).

Appropriately, the exhibition is interactive, designed with an eye and ear for fun. Red velvet theater curtains greet us at the entrance. A real piano is on hand for those inclined (and able) to play from vaudeville-era sheet music. Headphones allow us to listen to scratchy old cylinders containing the cutesy-pie trilling of forgotten stars like Blanche Ring, Frances White, and Irene Franklin.

Stunning short films from the Library of Congress, some a century old, provide a ghostly spectacle of longdead acrobats and dancers silently performing their acts for us across a gulf of decades. Later, Vitaphone films (very early talkies produced by Warner Brothers) allow us to experience the likes of hoofer Joe Frisco and a breathtakingly young Burns and Allen in their full glory.

But the exhibition, while accessible to the layman, also contains enough rare and interesting artifacts to be of interest to the jaded showbusiness buff. Yet there is a real dan ger that the uninitiated may walk away from this exhibition … uninitiated. “Vaudeville Nation,” apparently by design, downplays the contributions of individuals.

The visitor will likely walk away not retaining the names of B.F. Keith, E.F. Albee, or F.F. Proctor, who created the first show-business conglomerates and organized the circuits that crisscrossed the nation. Furthermore, vaudeville itself is never precisely defined, and the curators embrace a much looser definition of what constitutes vaudeville than is probably justified.

For example, there is a preponderance of material in the show (perhaps as much as a third) devoted to the picture palaces of the 1930s, vaudeville’s immediate linear descendants. The exhibition is further blurred by the many digressions devoted to burlesque, Broadway reviews, and nightclubs. The curator’s imprecision extends to music, in which such black pioneers as Ernest Hogan and Bert Williams, commonly thought of as belonging to the ragtime era, are described as “jazz.”

In the end, though, this is hair-splitting.The joy of encountering the sights and sounds of that magical period in American popular culture far outweighs the vagueness of the purported history lesson. Best of all, we get to encounter all this for free – fitting for this most populist of art forms.

Until April 1 (40 Lincoln Center Plaza, 212-870-1630).

Mr. Stewart’s book, “No Applause – Just Throw Money: The Book That Made Vaudeville Famous,” is available from Faber and Faber.