Broadway critics have not yet weighed in on "Monty Python's Spamalot," a new musical based on the classic 1975 film "Monty Python and the Holy Grail," but by the time they do, a great many audiences will have delivered their own verdict. After a five-week run in Chicago, the warm, hilarious, profoundly silly show is receiving rapturous applause in previews on Broadway. Yet the director, the legendary Mike Nichols, and the show's creator, Eric Idle, an original Python, are still tweaking it. Nichols, 73, and Idle, 61, sat down with NEWSWEEK to explain why. Idle arrived first. He was ready to talk.

NEWSWEEK: Surely you could've found someone more distinguished to direct this.

IDLE: It's funny, we had to give a little speech before the first show on Monday, so I was just rude. When they asked me who I initially thought of to direct, I said I went straight for the top--but Susan Stroman wasn't available. Seriously, Mike is so good for this. He keeps it from going over the top, so it doesn't get too muggy. Otherwise, it's just a revue. And he's always cutting.

You've cut whole scenes since Chicago?

IDLE: We had the witch-burning scene from "The Grail" in the show, and it worked OK. But it was sort of a detour. And if you can cut something, you should. We also had a dancing-cow number. That song was Mike's baby, and he killed it.

Based on the show last night, you haven't quite mastered the physics of cow tossing.

IDLE: Yeah, it's terribly hard. We had a big cow in Chicago and it was almost impossible to throw. [Nichols arrives] I was sure you'd forgotten about this interview.

NICHOLS: I was sure you'd forgotten.

I'm surprised to hear that you're still fiddling with the show. Are you dissatisfied with the standing ovations you've been getting?

IDLE: Yes. We want them to be flying ovations. [Nichols laughs] We want actual liftoff. It's not good enough for them to be standing and screaming.

NICHOLS: It's not. It's vulgar.

IDLE: The world of comedy is endless dissatisfaction.

NICHOLS: It is the nature of doing a show. There's always stuff to fix. And what's frustrating is that right as you're building it, it's disintegrating.

How do you mean?

NICHOLS: Little things build up over time. Little encrustations grow over the actors. On this show, we have this thing we do called "killing babies." Some nights you have to give up the laugh. Don't fall in love with the little face you make or the little squeak you do. I noticed long ago that there are two kinds of actors. There's the kind that get a little bit encrusted as time goes on. And there's the kind that get a little truer, about 4 percent truer every night--that's what we have on this show.

Launching this show in America, did you worry about losing any of the English sensibility?

IDLE: No, Americans have loved Python for many years. We used to believe it would never fly in America. That was our snobbery. "Oh, they'll never get this. We're too smart." [Laughs] It wasn't true at all.

For many of us, Python is a second language. Your actors must know that a lot of the audience could do their parts from memory--or "off book," as you say in the theater. NICHOLS: After a week of rehearsals, I said to Hank [Azaria, who plays four roles, including Lancelot], "Jesus, you know the whole French taunter part already!" He said, "Mike, I've been off book since I was 12." I was surprised by the euphoria from the audience every time the cast launches into a famous sketch.

IDLE: I think it's akin to doing a Beatles song. There's something very pleasant about the familiar. What's interesting is that we accept that emotion with songs, but the first time I toured, we got that with Python sketches. I think that's kind of new.

NICHOLS: It's new and it's old. It's the pleasure of a Shakespeare play.

IDLE: They are parallels with comedy. I memorized all of "Beyond the Fringe." I knew four whole monologues.

NICHOLS: Me, too. Exactly. "To my friend who very suddenly, violently--"

IDLE AND NICHOLS: "--vomited!"

I have no idea what you guys are talking about.

IDLE: [Laughs] See, that's exactly it. It was a comedy milestone, and we learned it. We did it on the playground. We can quote that, and people your age can do Python.

As a result, you're drawing a different audience than your standard Broadway crowd.

NICHOLS: Absolutely. When do you see young men lining up for the theater? And I already have three different friends whose 10-year-olds are obsessed with this show.

IDLE: One thing all the kids love is the [fake] horse riding.

Is it true that that joke--the clattering coconuts standing in for horses--came about because you didn't have money for horses?

IDLE: It was initially a radio joke. That's how they did it on radio. Then you see a guy come over the hill with the coconuts. It was just a pure visual gag. But when we were making it we thought, "Hang on, everybody can do that! We don't have to have f---ing horses! We can't afford it anyway." That reminds me, Mike: last night, when the head came off? Was that deliberate? [During one scene, the famed killer rabbit attacks a knight and swiftly decapitates him.] Because the head immediately popped off. Normally he holds it for a bit and then lets the head go. But last night, when his head flew right off, it was thrilling! Can we make sure that happens again? It got a huge roar.

NICHOLS: Absolutely. Of course.

Eric, what made you want to do "Spamalot"?

IDLE: I've always wanted to write a musical. And the time is right for it. We've gotten past "Phantom," the heavy musicals, the dramatic musicals, the visual musicals, and now it's time for comedy.

The producers of "Dirty Rotten Scoundrels" [sidebar] must be nervous about getting steamrolled by you guys. It happened to "The Full Monty," which came along at the same time as "The Producers."

NICHOLS: It could happen, but it could happen the other way too. We could be run over. There's no telling. You know, if it had been "Hairspray" and not "The Full Monty," then "The Producers" couldn't have run over it. There would have been two big hits simultaneously, and why not? The thing that you cannot fake is the thing that happens with the audience. "The Producers" had notorious trouble with ticket sales once Nathan Lane and Matthew Broderick left. Nothing against your marvelous cast, but your show doesn't depend on one cast member.

IDLE: No. We are really lucky that way. It's wonderfully reassuring because it means you're dealing with archetypes, and so your actors can be replaced.

Tonally, "Spamalot" is a departure from the film, which is raw and almost brutal. The show is quite warm. It wants to be liked.

NICHOLS: One of the things I like about this show is that it's still, to some extent, about cruelty. The things in the movie are not gone. They're buried a little deeper--because you have to be in a good mood to do a number. But the jokes are still based on people's heartlessness to one another.

IDLE: And that insane optimism. "I'm not dead yet!"

NICHOLS: I love how that's become a theme of the show.

IDLE: It's probably because of my nature, as opposed to the nature of the Pythons. I think if all the Pythons had been involved it would have been much more gruesome, don't you, Mike? I mean, if you let [Terry] Gilliam loose, the next thing you know there's blood everywhere.

NICHOLS: One of the things I love about the show is that it knows it has very little plot. And it enlists the audience's help in putting together a rudimentary plot. That's part of why we go to the theater: because of how much the audience is part of what's created.

Have the original Pythons seen the show?

IDLE: No. [John] Cleese saw a very early rehearsal, but that's it. They're all coming opening night. That will be interesting.

Is their approval important to you?

IDLE: Hmm. [Pauses] I don't know how to answer that. Their approval just to do it in the first place was vital. And a great act of faith. Not only did they say, "Yes, do it," they said, "We're going to stay out of it because it's your thing." So it'll be intriguing to see how they respond. They won't say, "Oh, that's great, well done." They'll say, "I would have done this," "Perhaps you should do this." [Laughs] And I'll go, "Well, you're too late. Do your own f---ing musical."