How actors go from zero to music virtuoso for film roles

Music coaches teach stars such as Keri Russell crash courses in violin, cello, and piano.

Hollywood is littered with tales of actors who go to painstaking lengths to learn a role, from Robert De Niro driving a cab as research for "Taxi Driver" to any number of svelte stars who gain huge amounts of weight to look like their characters.

But few feats of research seem to generate more fascination – and are so consistently rewarded come awards season – as learning a musical instrument. Whether it's Katherine Hepburn's portrayal of the pianist Clara Schumann in "Song of Love," Tom Hulce in the title role of "Amadeus," Geoffrey Rush as David Helfgott in "Shine," or Joaquin Phoenix and Reese Witherspoon as Johnny and June Carter Cash in "Walk the Line," audiences expect on-screen musicians to look, if not sound, realistic.

At the same time, musician roles raise questions over what's real and what's fake, when and where hand doubles are used, and whether prior musical training was needed. And if Tom Cruise can learn Haydn in five weeks, we wonder, why can't I?

Such questions resurface with the release of "August Rush," a new film about an orphaned 11-year-old musical prodigy who uses his gifts as a clue to finding his birth parents. Cast members spent over three months learning to play instruments, including Keri Russell, who portrays a concert cellist, Jonathan Rhys Meyers, who plays a rock singer-songwriter, and Freddie Highmore, who, in the title role, plays both guitar and organ and conducts a symphony orchestra.

While Rhys Meyers had some prior guitar experience, Russell and Highmore had to start from scratch learning their instruments and playing along to the professional recording that audiences hear in the theater. Director Kirsten Sheridan believes learning the instruments gave the actors a deeper connection to their roles and mostly eliminated the need for hand doubles. "We wanted them to feel the emotion of the music they were playing," she says.

Working with two teachers, Russell started with simple scales and worked her way up to the film's climactic piece, the Elgar Cello Concerto.

"Faking a cello is not like faking a guitar," Russell explains. "First of all, there are two very different hands. One is the fingering hand that's all up and down, and over and across. It would look really silly when your fingering hand is way up high when it should be down low. The bowing is also very specific."

Highmore's challenges were different. Although he didn't have to master any intricate fingerpicking or fast chord changes, the pieces were very loose rhythmically and difficult to sync with the recorded track on set. Jeff McErlaine, Highmore's New York-based guitar instructor, says the actor spent three to six hours each week on lessons, focusing almost exclusively on the pieces in the film. Ultimately, a hand double (the guitarist Kaki King) was used, although sparingly, and only because certain virtuosic passages were added too late in the filming schedule for Highmore to learn.

Actors realize that training their hands or fingers is only part of the process. Russell, for instance, watched hours of Jacqueline du Pré videos, observing the cellist's mannerisms and facial gestures. Highmore studied clips of Jimi Hendrix and Michael Hedges to better grasp the mind-set of a guitarist.

Margie Balter, a Los Angeles-based pianist who has coached many famous on-screen pianists, finds that actors are generally fast learners. "They're motivated, they have great instincts, and they're not going to fake it," she says. When Balter spent a year teaching Holly Hunter for her Academy Award-winning role in "The Piano," the actor wanted to understand the fundamentals and not simply fake her way through the pieces. Still, timing is a major factor. Balter had just five weeks to teach Tom Cruise a Haydn sonata for "Interview with the Vampire," and two weeks to teach Schubert to Barbara Hershey for "The Portrait of a Lady."

John Tibbetts, a film historian and author of the book "Composers in the Movies," believes the practice of actors learning instruments started with the rise of composer biopics in the late 1930s. It reached an early peak with the 1961 Franz Liszt biopic "Song Without End," in which the British actor Dirk Bogarde mastered several of Liszt's impossibly demanding piano works. "Bogarde can claim distinction with having most successfully faked it," Mr. Tibbetts says.

While some modern-day actors – notably Phoenix and Witherspoon – do the actual on-screen performances, warts and all, Russell was happy to just look credible in "August Rush."

"My poor, poor neighbors," she says. "How many times did they have to sit through that bad early few weeks of cello." She adds: "But it is a visual medium and they weren't going to be using my sound in the actual film."