The story of the birth of modern art can be told as a fairy tale—French impressionists marching out of the dark forests of Barbizon into the sunny countryside of Aix-en-Provence and the sparkling cafes of Montmartre. By contrast, the story of German art at the turn of the 20th century is fraught, fractured, and untold: It did not survive the Holocaust. Even Germans wanted nothing to do with German art history after that war.

An exhibition at the Frye Art Museum now is nothing short of a major excavation of artists whose views of what's modern are messy—and maybe closer to where we ended up in this pluralistic 21st century than impressionism, cubism, or any other single "ism." There hasn't been an American survey of these artists in 100 years. Even in their own country, they're only now getting a fair showing. The Frye's exhibition The Munich Secession and America is not only an aesthetic adventure, it's also part of an emotional coming home for artists exiled from history for reasons that had nothing to do with them.

In this adventure, there are dead ends. The question nags from the start: Um, was this art forgotten for a reason? This show is a particularly bold move on the part of the Frye, a laying-on-the-line of its founding collection, which is from the Munich secession; loans from European museums are mixed in with collection holdings. Just how good, important, and interesting is the Frye's collection when you can really see it in context? Is it a symbol of progressive, rebellious creativity or lame, backwater pretensions to greatness?

Germany has suffered from its own inferiority complex for centuries in art (there's even a book devoted to the subject, The Germans and Their Art: A Troublesome Relationship, for sale at the Frye bookstore). A search for legitimacy in and through art is meritocracy at its best, concerned with tradition, work, compassion, and hope about the future.

Here's what the Munich secessionists thought about those things: Unlike Gustav Klimt, the great gilder, of the contemporary Vienna secession, these artists believed in truth telling even if it meant ugliness. They believed that God's best qualities were Christlike, which is to say socialist, which is to say they painted the plight of the poor. They were starting to get interested in the obscure anterooms of the emerging field of psychology: dreams, the occult—territory the surrealists would later dive into. They foretold abstraction but resisted it (the shaded planes of bright color in Hugo von Habermann's 1911–1917 portrait of a woman bring to mind Tiger from 1912 by Munich-based Blue Rider Franz Marc, which clearly points to cubism and beyond, while von Habermann's semiconventional portrait points nowhere in particular). They also laid groundwork for the utopian integration of decoration, functional objects, and art that happens at the internationally influential Bauhaus.

Considered in the context of which-way art—forward or backward?—the Munich secessionists look tame next to, say, the Italian futurists, who published their fiery manifesto calling for the "hygiene" of war (they got it, to their ultimate dismay) in 1909, the same year that the Munich secessionists had their New York debut at the Metropolitan Museum of Art.

Formed in 1892, the Munich secessionists are credited as the first of the proto-avant-garde splinter groups. But their revolutionary spirit is not violent; in fact, it has an administrative tone. Instead of issuing a manifesto, the Munich secessionists wrote a "memorandum." Published in the extensive exhibition catalog, the memo contains three exclamation points, but is more characterized by the sedate: "We are prepared to make considerable sacrifices; everyone will do his best and submit himself to a jury, whose duties will be discharged by the executive committee serving at the time."

The secession was formed because the officially sanctioned exhibitions were growing too large and too domestic: Every Munich artist was allowed into the game, when the secessionists felt many deserved the bench. "Elite" is a key word in the memo. Its claim is that Munich art has fallen behind the world and must catch up.

Although exhibition design doesn't come up in the memo, the Munich secessionists were the ones to introduce what's known as the "modern hang," as opposed to the crowded "salon hang." Their first show, with breathing room for each work, included a golden geometric frieze, which the Frye has replicated in its galleries.

In 1909, when the Munich secessionists showed at the Met, a New York Times reviewer wrote, "Their sole unity of purpose lies in the avoidance of unity." It makes sense that in 2009, the Frye, in its presentation of the show (curated by Jo-Anne Birnie Danzker, director emerita of the Museum Villa Stuck in Munich) translates that description into "diversity." The introductory wall text includes the word "diversity" twice. It's an aesthetic and a political word, describing the collapse of hierarchies in art while also distancing the German artists from the notion of racial singularity.

Diverse is an understatement—these artists are all over the place. Munich secessionism is the anti-"ism." Though this show is an academic exercise, the paintings couldn't feel less academic. "We have witches burned at the stake, female crucifixions, and homoerotic wrestling," Frye curator Robin Held whispered excitedly, drunk on eclecticism, during the press preview led by Birnie Danzker.

And it's not just subject matter. It's style, too. Contemporary critics described the Munich secessionists as "brash" with a "poster style," but really that only applies to a few of them, including Franz von Stuck, with his striking neo-Greek designs. (Tucked away in a corner of the show is a standout painting by Stuck, of lovers kissing under a single, textured golden star.) Their subjects appear in so many guises: as if glimpsed through a clear window; as if scrawled using food, blood, and shit; as if consciously designed with an eye to glamour rather than come upon in nature; as if as unadorned as a close-up view of tree bark.

After the devastation of World War I, some of these artists were embarrassed by their idealized visions, while others with darker tones probably felt vindicated. Cartoonish pastoral myths by Max Kuschel and Ludwig von Hofmann's brightly colored paradises (one owned by Thomas Mann while he was writing The Magic Mountain) could not be more different from the brooding visions of Gabriel Cornelius von Max and the symbolist austerity of Oskar Zwintscher and Max Slevogt. (An early dark star, a landscape by Barbizon founder Theodore Rousseau, was borrowed from the Henry and is in the very small "guests" section of the show.)

Now that it's back out in the open, would it be better if the Munich secession disappeared again? Absolutely not. There's freshness and vitality here. Any isolated section in a Leo Putz painting is a patchwork of colored daubs that could stand alone as an abstraction (and does, in Sean Scully's work of the last 30 years). The lusciousness of paint and whiff of sexual aggression in a Hugo von Habermann nude is a living link to artists as disparate as Wayne Thiebaud and Balthus. Adolf Hoelzel's Dachau marshes melting into near-total abstraction are both early for the future and primal in feeling. Flat Jugendstil prints by Peter Behrens represent another system of art entirely, the Japanese. Wilhelm Trübner's gaudy forest heralds the coming of the only native German "ism," expressionism.

Pointing to Trübner's jarring painting during the press preview, Birnie Danzker said something fascinating: "You're looking at works that you think you don't like, as I have, but they become very interesting." This rings true. If it is, the exhibition is doing its job.

This article has been updated since its original publication.