I learned a new word this summer - "allosemitism." Coined by a Polish-Jewish literary critic named Artur Sandauer, the term describes a concept with which I am quite familiar - the idea of Jews as the perpetual "other." Allosemitism can embrace both positive and negative feelings toward Jews - everything, as the sociologist Zygmunt Bauman put it, "from love and respect to outright condemnation and genocidal hatred." At root is the idea that, good or bad, Jews are different from the non-Jewish mainstream and thus unable to be dealt with in the same way or measured by the same yardstick. The word cropped up during a recent symposium on Jewish and Roma (Gypsy) cultures that I attended here as part of a project called, significantly, "The Other Europeans." It was gratifying to find a term that so aptly describes the ambivalent ways in which Jews are regarded. And it was amazing to me that I hadn't come across it earlier, considering all my reading and writing on the subject, not to mention my experiences over the past decades as a Jew in Europe. We all know about anti-Semitism and the historic demonization of Jews. But anti-Semitism can be counterbalanced by an idealization of Jews and Jewish culture that also can be divorced from reality. "People who think Jews are smarter than everyone else don't have Jewish relatives," my brother Frank likes to quip. The Other Europeans project examines some of these issues by focusing on the relationships between Jewish and Roma cultures, particularly in the realm of music. The project statement doesn't use the term "allosemitism." Instead it describes Jews and Roma as having "transcultural" European identities "in both fact and imagination." This, it states, has led to the condemnation of both groups as "rootless," "parasitic," "degenerate" and worse, as well as to continuing anti-Semitic and anti-Roma outbursts. At the same time, it notes, "the same transcultural character of Yiddish and Roma music is romanticized and embraced by contemporary 'world music' pop culture, which frames it as subversive and transgressive and therefore 'hip.' " The Other Europeans project is the brainchild of the musician Alan Bern, an American who has been based in Berlin since the 1980s. It is sponsored by three Jewish culture festivals -- the Weimar Yiddish Summer Weeks, which Bern directs; the annual Festival of Jewish Culture in Krakow, Poland, which this year marked its 20th anniversary; and the KlezMORE Jewish Music Festival in Vienna. All three present and teach Jewish music and culture to a predominantly non-Jewish public. Bern, a key figure in the klezmer music revival over the past two decades, is a thoughtful observer of the sometimes uneasy cultural dynamics between Jews and non-Jews in Europe. "You define culture through interactions," he told me during one of our many conversations. "What defines something is often the point of view from which you regard it." How to define what is "Jewish" provides endless fodder for debate in post-Holocaust, post-communist Europe. Jews are few here now; Jewish communal life, though reviving in some places, is in flux; and Jewish cultural expression is often embraced or even perpetrated by non-Jews. Strict halachic definition may suffice for the religiously observant. But for Jews and non-Jews alike, that has always told only part of the story. And indeed, as experienced so drastically in the Shoah, definitions of what, or who, is Jewish often come from the outside. Is there, as the concept of allosemitism implies, a "certain Jewish something" that does so set Jews apart? The Jewish Museum in Munich has mounted an exhibit this summer actually called "That Certain Jewish Something." It takes a creative and rather provocative approach to explore the intangibles that can imbue objects, situations and even individuals with a sense of Jewishness. The museum called on the public to bring in an object the people felt had "a certain Jewish something" about it with a written statement about why they had chosen that item. More than 120 people, most of them non-Jewish or with only distant Jewish roots, answered the call. All the objects were delivered on one day, June 22, and then arranged in display cases with the stories behind them. The resulting, wide-ranging collection, as the museum puts it, provides "a multifaceted view into a very personal and modern picture of Judaism." Some of the objects are explicitly Jewish: menorahs, an old container for matzah, kitschy shtetl figurines, family silverware marked for meat and dairy, a Ten Commandments paperweight, a comic book called "Shaloman." But for many of the items - a flashlight, a rock, a tablecloth, a necklace, books, paintings, an ordinary pair of sneakers - "that certain Jewish something" is revealed only through their meaning to those who selected them. A set of faded snapshots shows a smiling, bespectacled fellow attending a party in a Mexican costume. The man who brought them in had found the snaps when he moved into a new apartment, and they apparently showed the previous tenant, a Jewish man who had passed away. An 11-year-old boy brought in a shirt from the Bayern-Munich football team because he had read that the team's president before World War II had been a Jew. The ordinary pair of sneakers belonged to a Jewish man. They in fact are a tangible symbol of the force of his faith: He wears them to the synagogue on Yom Kippur, he wrote, as they are made of cloth, not leather, which is prohibited on the holiday. That allosemitic, "certain Jewish something" is in what they represent, or how they are represented, not in what they actually are.