This is not a knock on a show that has been the unwanted child in a brood of Sondheim hits that stretch from A Funny Thing Happened on the Way to the Forum to Into the Woods. No, he's raising the alert level for good, practical reasons. Back in 1991, just before Assassins opened off-Broadway, the first Gulf War broke out. The patriotic climate was not ripe for a musical that showcased nine killers and would-be killers of U.S. Presidents; the show got mixed reviews and never moved to Broadway. A decade later a new, Broadway version was gearing up to open in the fall of 2001. Two days after Sept. 11, the producers shut it down. "There was no chance of an audience coming in with an open mind," says Sondheim. "I wouldn't if I were the audience." Now, 2½ years later, Assassins is finally, warily trying again. "I tell you, get your family out of town till we open," jokes the composer. "We seem to be the harbingers of disaster."

For some critics, what Sondheim and book writer John Weidman put onstage in 1991 was disaster enough. A carnival barker, under neon signs blaring hit the prez! win a prize!, opens the show by luring in a parade of customers like John Wilkes Booth, John Hinckley and Charles Guiteau, the "disappointed office seeker" who shot President James A. Garfield. Hinckley and Lynette (Squeaky) Fromme—wannabe assassins of Ronald Reagan and Gerald Ford, respectively—sing a duet about unrequited love, in their cases for Jodie Foster and Charles Manson. One musical number ends in an electrocution, another in a hanging. Samuel Byck, who plotted to kill Richard Nixon, talks about wanting to crash a 747 into the White House (a line from 1991 that hasn't been changed). How in-your-face is this show? Sondheim originally wanted to open it at the former Texas School Book Depository in Dallas. Says he, with a smile worthy of Sweeney Todd: "It would have been sensational."

Sondheim, 74, was padding around his ritzy Manhattan town house (Katharine Hepburn used to live next door) on a recent weekday afternoon, looking a bit scruffy in an oversize T shirt but talking animatedly about the show that he was always surprised got such a "virulent" negative reaction. The most celebrated Broadway composer of the past 30 years hasn't had a new show on Broadway in 10—since Passion, which ran for eight months in 1994. The days when Sondheim shows like Company and Follies seemed to be opening doors for musical theater are long gone. After years of work, Sondheim's latest show, Bounce, is on hold after two poorly received pre-Broadway tryouts. Meanwhile, he has been looking backward, adding six new songs to The Frogs, a 1974 show based on Aristophanes' play that will make its Broadway debut this summer in a revamped version written by (and starring) Nathan Lane. But Assassins is the Sondheim show in the cross hairs at the moment. Has its time finally come?

The germ of the show was planted in Sondheim's head back in the 1970s when he was judging scripts at a workshop for new musicals and came upon one called Assassins. It was a different, Manchurian Candidate–like story about a war veteran hired to assassinate a President, but Sondheim remembered it years later when he was discussing ideas with Weidman, his collaborator on Pacific Overtures. Their first thought was to create a musical about assassinations through history, starting with Julius Caesar. They eventually narrowed it to assassins of U.S. Presidents—each of whom gets a moment in the spotlight, voicing grievances both real and imagined, poignant and farcical. Sondheim sees the show as a comment on the dark side of the American Dream. "If you are led to believe that you can be President, so to speak, and you find out that you can't—that you have mistaken the kind of idealized dream for reality—you're likely to get angry," he says. "And maybe likely to want to kill a symbol."

Sondheim and Weidman have made only minor changes for the new production (directed by Joe Mantello) beyond including a new song, "Something Just Broke", written for the 1992 London version. It's a nice addition to a score that is (oddly, given the subject) one of Sondheim's most tuneful and accessible, with its stylistic echoes of American folk ballads, gospel hymns, Sousa-style marches and turn-of-the-century waltzes. Sondheim has little patience for the long-voiced criticism that many of his scores abandon melody for astringent experimentation. "I do what is required for each show," he says. Besides, melody is "a very tricky word," he says. "When someone says a tune is not melodic, they mean they can't hum it easily. And my claim would be, if I play it for you 10 times, you will be able to hum it."

Sondheim, the guru for a generation of musical-theater composers, won't comment on the state of the Broadway musical (he doesn't want to hurt any feelings) and says he doesn't see many musicals anyway. He prefers going to straight plays, watches movies at home on video (recent favorites: The Barbarian Invasions and Elephant) and listens mostly to symphonic music—"nonvocal, because the words are so distracting." With Assassins coming together, he is buckling down to finish three final songs for The Frogs ("I'm a slow writer, and I only have a month to do them, so it's tight"). Then he may turn back to his troubled Bounce, which he and Weidman based on the lives of Wilson and Addison Mizner, brothers who got caught up in everything from the Alaska gold rush to the Florida land boom. The show has gone through two directors, three titles and several approaches—and still seemed to miss the mark in a Washington tryout last year. "I don't know what to do with that show because I like it the way it is," Sondheim says. "That's what's baffling."

And is there one more Sondheim musical in the wings? "I'm at an age where the energy level is going down," he admits. "But I'm sort of fishing around at the moment." In the meantime, he'll be happy if an old musical called Assassins wins some new fans. "I have no idea what people will make of it today," he says. "I live in a liberal community, which is happy to bring into question things about this country. But you know, when people come in as divisively sensitive as they are these days—goodness." One thing is for sure: it's no time to leave town.