If anyone saw himself as a fixer, it was Shlomo Carlebach. With the extraordinary power of his original melodies, the wonder-working rabbi traveled around the world beginning in the 1960s, helping Jews who were suffering from drug abuse, loneliness and alienation from Jewish life. Ironically, “Soul Doctor,” the musical about Carlebach’s life and career, has itself been in need of repair. After a highly publicized flop at the Circle in the Square on Broadway last year, the musical returns, Off-Broadway this time, in its 11th incarnation. And now, the creative team believes, the musical has finally found its voice. The retooled show, which is currently in previews, opens this Sunday at the Actors’ Temple Theatre in Midtown.

Directed by Mindy Cooper and starring singer/songwriter Josh Nelson (not to be confused with the black-Jewish gospel singer, Joshua Nelson), the new production of “Soul Doctor” is modeled on a recent Yiddish-language production of the show in Montreal, which emphasized Carlebach’s music and downplayed some of the details of his life. Its Off-Broadway venue, a synagogue, is uniquely appropriate for the tale of one of the most influential rabbis of the 20th century.

First performed in a workshop at the Folksbiene Yiddish Theatre in 2007, “Soul Doctor” had staged readings at various venues in New York. The first full production took place at a theater in New Orleans in 2010; it ran the following year in Miami and Fort Lauderdale. It then ran Off-Broadway at the New York Theatre Workshop before opening on Broadway in 2013.

Jeremy Chess is a New York ophthalmologist who has produced “Soul Doctor” since the beginning. “It’s hard to find backers for a show that lost money on Broadway,” Chess told The Jewish Week, noting that the Broadway production (which opened prematurely, because a show that was in rehearsals at the same theater suddenly closed) was already in the red by the time it opened.

But Chess said that the show has “such a powerful dramatic component” that it begs to be staged. Carlebach’s music, he observed, brought out “both the meaning and the emotional component” of Jewish liturgy in a way that makes it accessible to Jews of all levels of religious observance. And he said that the creative team was thrilled to discover that the performance space had spectacular stained-glass windows that were shrouded in black crepe. Chess said that the creative team “decided to embrace the building’s synagogue origins rather than camouflage them.”

The Actors’ Temple is located in Congregation Ezrath Israel, founded in 1917 as the West Side Relief Organization; Al Jolson, Edward G. Robinson, Sophie Tucker, Jack Benny, Milton Berle and other famous entertainers were on its membership rolls. There is no wing and backstage space (the only way to get off stage is to go onto a fire escape), so it is difficult for performers to make entrances and exits. Cooper, the director, thus decided to have the entire cast remain on stage for the duration of the show, as if it is a traveling actors’ troupe. In taking this approach, Cooper (a former ballet dancer who made her own Broadway bow in Andrew Lloyd Webber’s “Song and Dance” in 1980), said she was inspired by Carlebach’s hangers-on, who were known as his Holy Beggars.

“We watch the actors change clothes and tell Shlomo’s story across the decades,” noted Cooper, who recalled that she was “raised on Carlebach’s tunes — I grew up on minor thirds” at Beth Tfiloh, a Modern Orthodox synagogue in Baltimore. She decided to let Carlebach’s music “speak for him” rather than delve too deeply into his biography. She likened her approach to that of “Jersey Boys,” in which the “script is a beautiful platter for the songs.” Nelson, she said, is the “heir apparent” of Shlomo, in bringing new melodies to synagogues, camps and youth groups. “He’s also an amazing guitar player,” she added. “He can shred at a moment’s notice. We’ve incorporated that in the show.”

Nelson, who studied jazz music at Boston University before having a religious awakening of his own in his mid-20s, speaks about Carlebach’s music with great reverence. “He believed in the transformative power of song,” he said. “He was a wide-open human being who believed in loving the world.” Nelson emphasized that Carlebach’s encounter with the African-American jazz musician Nina Simone (played by Dan’yelle Williamson), which is a central aspect of the plot of “Soul Doctor,” had a tremendous impact on him. “They were two kindred spirits who became magnetized to each other. Carlebach’s first record contained gospel music.”

One important factor in Nelson’s feelings about Carlebach is that he and Neshama Carlebach, the rabbi’s daughter and one of the foremost interpreters of his music, are currently dating each other. Because Nelson is not an actor, he said that he has found it extremely helpful to talk about Carlebach with his daughter. “She really understands what drove him,” Nelson said. “It’s such an extraordinary gift to be dating her and playing her father.”

Danny Wise penned the script for “Soul Doctor.” In tinkering with the script over so many drafts, he said, he has aimed to “hone in on the inspirational and theatrical elements of his life.” Although Wise is aware of the controversy that swirled around Carlebach after his death, in which the rabbi was accused of sexual improprieties with women, he called Carlebach a “very complex person with a benevolent, loving, selfless, expansive, romantic view of the world. He was a charismatic, free-loving, rock star rabbi who fell in love with everyone he met.” In the process, Wise reflected, Carlebach “helped to reshape Judaism in America.”

The new production, which Wise has not yet seen, sounds to him like just what the “soul doctor” would have ordered. “He never liked to perform up on a stage,” Wise recalled, “if he could stand in front of it and create a more intimate, warmer vibe.” This production, he predicted, will “make the audience feel more of a connection with Shlomo. It will be like a kumzitz (song session in Orthodox Judaism, typically with Carlebach tunes) — a “sitting around the campfire listening to a story.”

“Soul Doctor” opens on Sunday, Dec. 14 at the Actors Temple Theatre, 339 W. 47th St. Performances are Mondays, Tuesdays, Wednesdays and Thursdays at 7 p.m., Saturdays at 8 p.m., Sundays at 6 p.m., and Wednesdasy and Sundays at 2 p.m. For tickets, $79.50 ($99 during Chanukah Week), call Telecharge at (212) 239-6200 or visit telecharge.com.