In an interview for Sweeney Todd over at the Telegraph, Sacha Baron Cohen goes into lots of detail about the process of learning to sing for the role. He tells a long anecdote about having his mother look up a singing teacher for him in the Yellow Pages, and then finding out the woman not only never heard of him, but also never heard of Tim Burton, Johnny Depp or the musical Sweeney Todd. "I ignored everything she said and went to the set the next day," he says. When made to audition for Sondheim, Cohen says he was unable to hit a crucial high note, but came up with a unique solution -- "I brought in a very fat female opera singer to sing the final note." Apparently, that was good enough to gain him Sondheim's approval.
Cohen also talks at length about his alter-egos Ali G and Borat, and says that he's come to realize that the popularity of the Borat movie means he'll never be able to do the character again. "Admitting I am never going to play them [Borat and Ali G] again is quite a sad thing," he says. "It's like saying goodbye to a loved one. It is hard, and the problem with success, although it's fantastic, is that every new person who sees the Borat movie is one less person I 'get' with Borat again, so it's kind of self-defeating form, really. It's upsetting, but the success has been great." Of course, the interviewer tries to get some info out of Cohen about Bruno, the next character he'll be taking to the big screen, but Cohen pretty much stops him cold. He's not opening his mouth about that.