A perceptive listener might have recognized chords from 'Jesus Christ Superstar' being pounded on a piano in a cramped rehearsal space on West 30th Street in Manhattan on Thursday night, but not the potentially sacrilegious way this musical was being performed. Standing in the center of the room, Peaches, the diminutive dynamo of raunchy electronic rock, was singing the entire libretto alone, just as she will in her one-woman show, 'Peaches Christ Superstar,' which was to begin its North American tour on Friday in Boston. As she sang her way from the Last Supper to Jesus' trial before Pilate, Peaches cycled through nearly every character from the Gospels, embodying them in her voice and face: a dainty, mocking Herod; a guttural Caiaphas, the high priest; and a bruised Judas hurling insults at Jesus so heatedly that it raised the veins in Peaches' ruddy face. Then she noticed she was being watched and suddenly became very shy. 'Oh,' she said meekly, 'I guess I'm on trial.' The real surprise of 'Peaches Christ Superstar,' an unlikely holiday show to be performed on Saturday at the Concert Hall on West 64th Street in Manhattan and on Sunday at the Music Hall of Williamsburg in Brooklyn, is its abundant sincerity: It is a stripped-down incarnation of 'Jesus Christ Superstar' from one of the last musicians you'd expect to have any reverence for the material or its subject. 'I'm not trying to push buttons with this,' said Peaches, who has long, bleached-blond hair shorn at the sides to its black roots. 'I see it as one of the basic human stories: Someone with good intentions tries to put forward something that he believes in, and then it all goes wrong.' You could see how anyone's inner schoolmarm might be roused by a production that combines show tunes, spirituality and Peaches, given her reputation as a purveyor of sexually charged techno-rock music and the ringleader of live shows that are sweaty, fetishized, spandex-and-smeared-mascara affairs. (The title of her biggest dance-floor hit cannot be printed here, but it endorses sex as an analgesic.) Back when Peaches, who is 44, was still Merrill Nisker, a nice Jewish girl from north Toronto, she grew up in a household filled with the gentle warblings of Barbra Streisand and Neil Diamond, and the cast recordings of 'West Side Story' and 'Hair.' At 15, Peaches said, a friend turned her on to 'Jesus Christ Superstar,' and it transformed her. In that early collaboration between Andrew Lloyd Webber and Tim Rice, whose original recording featured the rock singers Ian Gillan and Murray Head, Peaches said she heard 'a straight-up prog-rock extravaganza' that still surpasses hit jukebox musicals like 'Movin' Out' and 'We Will Rock You.' 'I find them, to be honest, quite trite and quite annoying,' Peaches said. 'I love the Queen songs, I even love the Billy Joel songs, but I don't want to hear some daft dialogue for the sake of it.' After many years spent clandestinely singing the 'Jesus Christ Superstar' songs in her bedroom, Peaches was asked this year by the Hebbel Am Ufer Theater in Berlin, where she now lives, to create a show there. She suggested 'Peaches Christ Superstar,' and to her surprise, the theater said yes. 'I opened my big mouth and said I would do it,' Peaches said, 'and then I had to go back and go, 'Oh my God, how am I ever going to sing this?'' With the help of her frequent collaborator Chilly Gonzales, a musician and producer who has also worked with pop singers like Jane Birkin and Feist, the score of 'Jesus Christ Superstar' -- which features at least nine principal roles that range from tenor to bass -- was arranged for piano and transposed to fit Peaches' vocal range. The power of such a minimal arrangement, Gonzales said, was that it was 'denying one of the most potent parts of Peaches' show, which is the sexual stuff.' He added: 'Peaches has always been a great singer. It's just that when people's sexual taboo buttons are being pushed, they maybe don't realize the level of the music or the drama.' Audiences almost didn't get to see any of this. In February, while preparations for the show were still under way, Peaches wrote on her Twitter account, 'PEACHES CHRIST SUPER STAR CRUCIFIED BEFORE OPENING NIGHT!' She further explained that the 'German authorities' that control the rights to 'Jesus Christ Superstar' would not grant her permission to perform the music. In an e-mail, Bettina Migge-Volkmer, the managing director of Gallissas, the Berlin agency that administers the rights to 'Jesus Christ Superstar' in Germany, wrote that Peaches did not initially seek a license to perform the show and that the company learned about it on the Internet. When Peaches did request the license, Migge-Volkmer wrote, she was concerned about images she saw online that depicted the singer on a set that featured 'a crucifix in phallus form,' leading her to believe that 'Peaches Christ Superstar' would be 'a takeoff of the original work.' At the instruction of the Really Useful Group, Lloyd Webber's London-based production company, Gallissas initially denied Peaches' request for a license. (A spokeswoman for the Really Useful Group confirmed this account.) But after further discussion among the various parties, and the intervention of Rice, who said that the show should at least be given a tryout, 'Peaches Christ Superstar' was allowed to proceed in March, eventually being performed about 10 times. Peaches said the cross she was using in her North American performances would be different, 'more labia than it is male.' (Migge-Volkmer, who attended a Berlin performance, wrote, 'Peaches has such a fantastic and unique stage presence that such props are unnecessary -- an empty stage would have sufficed.') Catching her breath after her three-hour rehearsal, Peaches found it somewhat difficult to explain exactly how she planned to portray so many different characters so distinctly. 'It sounds a little hippie,' she said, 'but it's about finding the part of you for each of the parts in the show.' Judas, she said, came from the gut; Pilate from the shoulders (because of his pride); Mary Magdalene from the heart and head; and Jesus, she said, came from 'putting your two feet on the ground and trying to be really centered, because at any moment you could lose it.' But the true challenge of her tour, Peaches said, was not the volume or the scope of the material she is required to master. Rather, she said: 'It's the first time I won't be smoking weed at all, which is really hard for me. I like to work hard and I like to play hard.' 