Wikipedia & Na Nach Nachma
Yesterday, my friend Breslever posted What's Na-Nach-Nachman?
This morning, I noticed that Wikipedia also has an entry about this that contains the following information:
"Not all Breslover Hasidim use Na Nach Nachma (some groups actually oppose it) and not everyone believes it is an authentic writing from Rebbe Nachman. The following are some of the diverse opinions:
Rabbi Odesser believed the "Letter from Heaven" was a genuine miracle, pointing out that the bookcase where the petek (note) appeared was locked at the time, and he had the only key. His followers believed in the miracle also. They continue to this day to chant the phrase as a "Song of Redemption" for the coming of the Jewish Messiah. Odesser's personal account of how he found the Letter has been translated into English under the title The Letter from Heaven: Rebbe Nachman's Song.
In May 1984, Rabbi Moshe Feinstein wrote a letter of approbation, endorsing Odesser's efforts to raise funds for publishing Rebbe Nachman's books. In this document, Feinstein said: "I am writing on behalf of a most unusual individual, Rabbi Yisroel Dov Odesser, shlita, from Israel. This individual is a gaon of Torah. I had the pleasure of recently meeting with him and was inspired by a secret document which he possesses." This seems to imply that Rabbi Feinstein thought the letter was authentic, although he did not explicitly say so. (The Letter from Heaven: Rebbe Nachman's Song, p. 2)
Some people believe that the letter was a note written to someone by Rebbe Nachman when he visited Tiberias during his pilgrimage to Israel in the early 19th century. Somehow it was placed in the old book, but Odesser's finding it was a coincidence (or miracle of timing), as was the reference to someone eating on the Fast of Tammuz.
Still others believe it was a well-intentioned forgery, written by one of Rabbi Odesser's fellow students in order to cheer him up after he got depressed from breaking his fast. (See The Writing on the Wall, which expresses this opinion.)
Rabbi Zev Reichmann (head of the Yeshiva University Mechina Program, student of Rav Aaron Soloveitchik, and son of Rav Herschel Reichmann) notes that many within common Orthodox society hold the view that people who wear "Na Nach Nachma" yarmulkes (see below) are not considered to be real Breslovers. (This view clashes with the traditional Breslover notion that whoever, with a pure heart, considers himself to be a Breslover, is a Breslover. As noted on the Breslover Hasidim page, the Breslov movement is not centralized and does not have an official membership list.)
Whatever the origins of this mantra, it is now very popular among certain sub-groups of Breslover Hasidim, and has been incorporated into both traditional and contemporary Jewish music. During the millennium fervor before the Year 2000, the Na Nach Nachma was widely distributed and publicized in Israel, appearing on bumper stickers, billboards, graffiti, etc. It has also been used on jewelery and amulets.
More recently, some people have begun to wear it on large white knitted yarmulkes with a little tassel on top. (These hats are a modification of a traditional white yarmulke that has been worn in Jerusalem for centuries. That style, in turn, apparently evolved from the medieval Jewish hat with the ball on top -- hence the tassel.) During the time that Reb Odesser was still alive, some of his followers were already wearing large white yarmulkes, but without the mantra on them. Na Nach Nachma yarmulkes in other colors are also appearing on the market now.
The mantra continues to be chanted by both Hasidic and non-Hasidic Jews, as well as some non-Jews who use it as a form of kabbalah meditation. Those who chant it are sometimes referred to as "Na-Nachers". Among some groups of Sephardic Jewish youth in Israel, it has become a sort of rallying cry for returning to traditional Judaism, although not necessarily to mainstream Breslov."
UPDATE: Will the Real Breslov Please Stand Up?