Once the mainstay of the entertainment industry, vaudeville is all but forgotten today.

Reg Bacon wants to change that.

From the late 19th century to the early years of the Great Depression, Bacon said nearly every town in the country had a venue where people could watch singers, dancers, jugglers, musicians, comedians, contortionists, magicians, ventriloquists, performing animals and who knows what else.

It's all gone.

Bacon, a Newburyport resident who calls himself "an all-but-retired acrobatic juggler, comic dancer and jazz/ragtime banjoist," will take his audience through the entertainment form's rise and fall Sunday when he presents "A Vaudeville Retrospective" in the program room at the Newburyport Public Library.

Bacon describes the hour-long retrospective as "an illustrated lecture, performance and exhibition" and himself as "The Last Living Vaudevillian."

He emphasizes that the retrospective is not a nostalgia show or a wish to turn back the clock.

Instead, Bacon will use digitally projected graphics, audio and video clips and some live performance excerpts to trace the history of what was once America's premiere form of entertainment.

A graduate of the Harvard University program of museum studies, Bacon wants to show the "interconnectedness" of the arts, sciences and economics — and clear up a couple of common mistakes people make when they think about vaudeville.

"We're far enough away from it so that nobody knows what it was," Bacon said. "Everybody thinks they know, but what they remember are misconceptions. The major misconception is confusion with blackface minstrelsy and raunchy burlesque."

A typical vaudeville show consisted of several acts unconnected by a plot and playing to a general audience. The acts were generally considered cleaner and more refined than other variety forms.

The term "vaudeville" was in general use by the late 19th century and may or may not have been derived from the French, Bacon said.

"The idea was to dress up the variety show, make it European, classy," he said.

At its peak in the early 20th century, he said, there were more than 4,000 vaudeville theaters around the country. There were as many as 50,000 performers.

The Great Depression and the advancement of technology were two factors contributing to the demise of the entertainment.

With money scarce in the Depression, it became cheaper for theater owners to book movies, rather than pay entertainers and support personnel.

Radio, and later television, allowed people to be entertained in their homes, for free, rather than go to a theater.

Bacon's interest in vaudeville was kindled early. His father was an early 1940s nightclub sleight-of-hand artist, and his grandmother was a movie house pianist in the days before "talkies."

A journalist when he first graduated from Syracuse University, it was a newsman's natural curiosity that led him to delve into the history of vaudeville as he built, with his wife L.J, Newton, a 30-year performing career.

"How could I be involved in this without digging and searching for the roots of it all?" he said.

Since he essentially retired from performing, Bacon has been working with Emerson College in Boston on a permanent exhibit on Boston's theater history that will open next spring at the college's Paramount Center, in the building that was once a theater of the same name.

IF YOU GO

What: "A Vaudeville Retrospective — An Illustrated Lecture, Performance and Exhibition" presented by Newburyport's Reg Bacon

When: Sunday, 2 p.m.

Where: Newburyport Public Library program room, 94 State St.

How much: Free