Johnny Depp and Helena Bonham Carter in Sweeney Todd Leah Gallo/Courtesy of DreamWorks

In terms of the singing, it's interesting, because neither Johnny Depp nor Helena Bonham Carter have the traditional kind of theatrical voices that generally handle Sondheim's stuff, so they sing in a slightly more pop style. But I think it works really well because it kind of sets the characters off, especially since they're in cahoots, as it were, it sets the characters more in tune with each other and apart from the rest of the ensemble.
Well yeah, I mean it was interesting because I didn't really go out of my way to do this, but…I knew Johnny didn't sing and Helena didn't, and I cast Alan Rickman who's not a singer and Sacha Baron Cohen who's not a singer. So pretty much the main cast aren't professional singers. And even the kids, except they're — you know, they're good singers, the kids — I mean, but even then, they're not professional. So that became weirdly important to me, in the sense that, not being trained or professional singers, they just gave it something else that you might not get on stage. I'd heard other people sing it more "professionally," as it were, and they just almost relied too much on that. They were almost like…it's like if you can really sing Sondheim then you sing Sondheim, you know what I mean? And I remember Stephen saying to me once, "I'd much rather have an actor sing it than a singer act it." And I think that was true in this case. And this felt like, because they couldn't rely on their musical expertise, the performances were good and they just sort of relied more on that kind of quality they could give it. And I don't know, I just appreciated it more.

The emotion of the two leads, of Mrs. Lovett and Sweeney Todd, combined with the actions they have to perform, are so intense that you can't help but feel that at certain points when they are — when they appear to be playing physically exhausted, they really are physically exhausted.
Yeah. Well it's hard work belting out those numbers! No, I mean, no, I think they both gave — for me, one of the things that was important was just them giving their roles sort of a very quiet undercurrent of emotional loss and longing and sadness and anger. And that kind of old horror-movie acting where it's kind of still; you know, some of my favorite moments are just Johnny looking out the window and, just by not doing anything, conveying rage and sadness and loss. I mean that, to me, is what I like in a movie; that, to me, is very exciting. And stuff that's not just said; that kind of Zen kind of acting, of being able to do something very still.

It's like certain moments you find with, say, Peter Lorre in something like Mad Love when he's not doing anything, really…
Absolutely. That was one of our inspirations. And there's something so beautiful about that.

Did you use more of the evolving tools of digitally manipulating the image to get that kind of feel and atmosphere you want?
To some degree. But, in fact, one of our main goals on this one was to not overdo that. Obviously you can do almost anything. But we kind of kept the green screen to a minimum. Color manipulation is left to a minimum too, because, I mean, with Dante Ferretti as the production designer, Colleen Atwood doing wardrobe and Darlusz Wolski as D.P., you don't need things like that; you're going to get what you want on the set! We just felt it was important to have the actors be in the environment, even down to the color scheme. We did this on Sleepy Hollow. We tested the blood color, we de-saturated the color in the actual sets and costumes so that it wouldn't be like, the actors see the movie and go, oh, shit, I didn't realize this was what my character was looking at. They could react properly to what they were seeing, actually do it. Also, if I just had to be on a green screen all day long every day, I think I might kind of go nuts. I like being in the environment.

As you move on in your life and career as a filmmaker, is it more of a challenge to find the kind of material that excites and animates you?
I don't know. I mean this one really did. So I can't say. I'm still kind of on this. I did really enjoy this. And, I mean, things like Johnny and I have been talking about — like these old horror movie actors and that kind of style of acting for such a long time — this was kind of the first time in a while I've been able to really do that. And that was so exciting. As was having music on the set and all that — really exciting. So it may take me a little time to get over this one.

So you're going to promote this, and then enjoy being a new father a little more?
I think that might be a good idea — might turn out to be a very good idea!