When Matisyahu’s signature dreidel-shaped disco ball is lowered and the devoutly religious reggae-rapper takes the mike at the 9:30 Club on Wednesday, it probably won’t be his music that fans are talking about.

The 32-year-old Hasidic performer first made headlines the week before ­Hanukkah when he shaved off his iconic beard and tweeted: “No more Chassidic reggae superstar.”

The artist’s untrimmed beard was central to both his musical persona and his piety, since many Hasidic Jews believe that male facial hair is sacred. It’s also an outward symbol of their religious fervor.

Since Matisyahu burst onto the scene in 2005 with the Top 40 hit “King Without a Crown,” his lyrics have been filled with his love of Torah and devotion to God, albeit with a Caribbean patois. He’s known to sing the key Jewish prayer, the Shema, at his concerts, and his fans are largely Jewish, though he does draw some rastas.

For Matisyahu, shaving his beard is akin to Tim McGraw taking off his cowboy hat. In a stark photograph that shows him cleanshaven and without his Hasidic black garb, he goes on to tweet: “Sorry folks all you get is me . . . no alias. When I started becoming religious ten years ago it was a very natural and organic process. It was my choice. My journey to discover my roots and explore Jewish spirituality — not through books but through real life. I felt that in order to become a good person I needed rules — lots of them — or else I would somehow fall apart. I am reclaiming myself. Get ready for an amazing year filled with music of rebirth.”

Then last week he kicked a female photographer who was taking pictures at his Hanukkah show in Brooklyn. He tweeted that he “snapped” because of the flash in his face. He later issued an apology, saying he “reacted impulsively.”

Befuddled fans have flooded Facebook with questions about the Grammy-nominated singer, who is a hero to some in the Jewish world. He was the most visible example of the blending of an ultra-
Orthodox religious lifestyle with the creative counterculture of reggae and hip-hop. Hasidic Jews separate the ­sexes, for instance, and married men are forbidden to touch women who are not their wives or blood relatives. (Matisyahu reportedly once had to turn down an invitation by Madonna to hang out at a Passover Seder.)

Matisyahu declined to be interviewed for this article.

But California-based Rabbi Eliyahu Fink, who writes the blog Fink or Swim, called the tweet “The Shave Heard Around the World.”

“Is his music truly good enough that he will continue to be successful when he is no longer a poster boy for anything other than himself?” asked the irreverent online magazine Heeb, which also joked that the tweet by the “artist formerly known as Matisyahu” was so shocking “it even triggered a JTA [the global Jewish information service] news alert which is normally reserved for terrorist attacks.”

Was the Hasid in the hoodie — who is known to fuse beatboxing with orthodox Judaism’s style of songful prayer — forgoing his faith? Or was he simply dialing back his belief? Would his highly religious lyrics — like those to “One Day,” which was played as background music in some television coverage of the 2010 Vancouver Olympics and asks God for a day without violence — vastly change?

So far the answer appears to be no. Matisyahu has been photographed wearing a yarmulke and tweeted that he would pray just as always. On his Twitter account, he also thanked fans who made him kosher food while on tour.

But the events have stirred a passionate debate about just how and if the two worlds can blend. A Chabad-Lubavitcher rabbi who knows Matisyahu well, but who asked not to be named, said he felt the pressure was just too much. “While Reggae mirrors some of the warmth in Hasidic life, it has nevertheless a looseness and freedom that just doesn’t jibe with Jewish structural life,” he said. “I pray he finds his way back.” The rabbi’s words speak to a long-running debate in the Hasidic Jewish community: What is the relationship between creative expression and devout religiosity?

It’s a struggle chronicled in the Chaim Potok novel “My Name Is Asher Lev,” in which a Hasidic painter struggles to balance his art and his faith.

Lani Santo is executive director of Footsteps, a secular organization that provides support to those who leave Judaism's ultra-religious communities. The organization’s Internet mailing list was flooded after Matisyahu’s shaving tweet. “Across the board it’s very challenging for our participants to balance the pursuit of individual creative expression with an ultra-Orthodox lifestyle. There’s not a lot of gray areas,” she said. “What Matisyahu worked to do was really an anomaly in that community.”

Matisyahu is known as a Ba’al T’shuva, which means he was born a secular Jew, but decided to take on a religious lifestyle. He was born Matthew Miller and was a musician who, by his own account, started taking hallucinogens and following the rock band Phish on tour. But he changed his name after becoming a follower of the Chabad-Lubavitch movement, a branch of Hasidic Judaism that is seen as more open than others because it reaches out to unaffiliated Jews, often on college campuses, and to Jews living abroad.

In many ways, Matisyahu was their most famous member, becoming Billboard magazine’s reggae artist of the year in 2006. (He left Chabad to explore other branches of Hasidism in 2007, saying, “I felt boxed in.” But he continued, for a while, to live with his wife and children in their official headquarters of Crown Heights, Brooklyn.)

“It’s a really fascinating moment. But for young Chabadniks who were excited by Matisyahu’s success as a validation of their entree into the mainstream, I’m sure it’s disappointing,” said Sue Fishkoff, author of the book “The Rebbe’s Army: Inside the World of Chabad-Lubavitch.”

“He’s a young man searching for his spiritual path,” she said. “He may go through other iterations, like many of us do.”

While some of his fans wonder if he shaved to bolster ticket sales, his friends say they respect what they see as his honesty about his spiritual journey. “It will be interesting to see how things will play out — if he keeps the signature beard and payos [sidelocks] off,” said Erez Safer, chief executive of Shempseed, a recording label that has worked with Matisyahu and other religious musicians.

“It had become his brand.”