He may be ambiguous as the slithering Professor Severus Snape in the "Harry Potter" movies, but there's no second-guessing Alan Rickman's character, Judge Turpin, in "Sweeney Todd: The Demon Barber of Fleet Street."

Turpin -- to cut to the chase -- is one bad dude. But the interesting thing, is, the esteemed British actor doesn't play him that way.

"I just play the character -- I don't judge them as good, bad or anything," Rickman said in a call from London this week for an @ The Movies interview. "You just do what's appropriate for that character. He's a very contained person. Therefore, you have to choose to do little. There's a lot going on in the minds of Sweeney and Judge Turpin, and that's what makes them such good adversaries."

In the film, Turpin provides the catalyst that turns London barber Benjamin Barker (Johnny Depp) into Sweeney Todd, a straightedge razor-wielding madman who seeks revenge on the judge after he wrongly sends Barker to prison in Australia for 15 years.

But it's not so much the prison time that Todd seeks vengeance for, as it is the devastating fate his wife and daughter suffered at the hands of the corrupt Turpin.

Adapted by Tim Burton from composer Stephen Sondheim's smash Broadway musical, "Sweeney Todd" presented a unique challenge for Rickman, Depp and Helena Bonham Carter, who plays Sweeney's meat pie-making accomplice Mrs. Lovett: none of the actors had sung on film before, if at all.

At least Rickman had the benefit of singing on stage before, but he downplayed the significance of it.

"All I'd ever done was a song in 'Private Lives' in the theater," Rickman said of the production he played in London and on Broadway. "Noel Coward's music is still great, but it's not quite the same as Mr. Sondheim."

Despite his lack of vocal experience, Rickman, 61, remained undaunted by the prospect of singing in a film musical -- even one that the famed composer famously made so untouchable until now.

"It's scary and exhilarating, but the scale swings far more in the favor of exhilarating. Maybe that has something to do with getting older," Rickman observed. "You look for the adventure more. What else is life about, really? Especially for an actor, it's a much more interesting life, instead of just trying to repeat yourself all of the time. I couldn't have been happier, really. What was the worst that could happen? I would get fired."

Theater In His Blood
Fortunately, "Sweeney Todd" worked out quite well for Rickman, and it couldn't have been any more rewarding. As a veteran of both film and stage, the musical proved to be the ultimate marriage of the mediums.

"With a great piece of theater like 'Sweeney Todd,' it reinvents the form in cinema because it's not like a typical musical where it's like, 'And now it's time for the big number.' I enjoy the way the song moves into speech and the speech moves into song, and you're never quite sure where one begins and the other ends," Rickman said. "Also, I like that fact that it's all pretty much played in close-ups, apart from the street scenes, so you get to hear what people are thinking, rather than see them dancing."

And then there's the blood -- and plenty of it.

"It's probably the first and only time where you'll get Sondheim's 'Sweeney Todd' with full blood and messy pies. The wardrobe people would never let you do that in the theater," Rickman laughed.

The prospect of dialing back the production begs the question: How would Burton fare as a theatrical director?

"He'd have to hand over a bit of control, so I'm not sure," Rickman said, chuckling. "And that's not to say that he's a control freak -- he's not -- he's incredibly open to what you do. But you're very aware that he's a man of particular vision who's walking up and down on the set with this enormous Jack-in-the-box quality. At some point in theater, the director just has to sit in the dark and shut up."

At least for a time, in "Sweeney Todd," Burton keeps his audience in the dark as to just how bloody the film is. And while a good part of the first hour of "Sweeney Todd" is relatively free of it, the director makes up for it by turning the spigot wide open for the film's second half -- so much so that Rickman believes that the blood deserves to be elevated above its prop material status.

"There's so much blood that it sort of becomes a character. It's got different personalities," Rickman said. "That's what's brilliant about the way Tim handles it. Sometimes it's like a quiet curtain of blood, and others, it's like a volcano."

While Rickman is happy that people respond strongly to the sight of blood in movies -- thus achieving the desired suspension of disbelief -- in some ways he's perplexed why they are conditioned to.

"I think it's so odd that people get so upset about the sight of blood in art, but not in real life," Rickman said. "People will carry on eating their dinner while people are getting their limbs blown off on the TV news. But somehow if you put it in a story,' people say, 'Oh, I'm going to pass out.'"

Of course, on the set, the sight of the "blood" was decidedly different.

"My memory of it was that it was bright orange and it just tasted of sugar," Rickman quipped. "I didn't see it quite the way you do."

Team 'Todd'
While Rickman and Bonham Carter both appeared in the recent "Harry Potter and the Order of the Phoenix," "Sweeney Todd" marked the first time that Rickman worked with Depp or Burton. Rickman said that, given Burton's friendly demeanor, he doesn't quite understand the "quirky" label that so many people have bestowed on the director.

"If you have hair like that, people call you quirky," Rickman mused about the director's distinct mop-top. "People like to get out their neat rubber stamps with that word. I don't know what 'quirky' means. If it means 'individual, unique and too thine own self be true,' then fine. He's a visionary and an artist."

Nothing really surprised Rickman about working with Depp for the first time, mainly because he ended up being just as others described.

"I heard rumors that Johnny was an incredibly nice guy -- and he was," Rickman said. "He's just a teammate on the set. That's a big thing when you're carrying the movie and it's a title role, yet you're willing to be open and ready to laugh. He was completely un-pompous. It was very freeing for everybody."

And that freeing approach suits Rickman perfectly. Like Depp and Burton, the actor makes it a point to take his work seriously, but not himself.

"You've got to be ready to laugh. You've got to know on some level it's just a movie," Rickman said. "It's got to be seen through the personalities of the people in it and fed through the personalities of the people making it. So you have to be generous of yourself to the piece of work. Otherwise, it's just an ego exercise. What's the point of that?"