LONDON — A drama set in the world of string quartets from a director making his feature debut may have seemed an unlikely candidate to draw significant attention among the lineup at this year’s Toronto Intl. Film Festival, but Yaron Zilberman’s “A Late Quartet” is a hot ticket, with an ensemble cast to die for.

Zilberman’s debut script, co-written with Seth Grossman, attracted Philip Seymour Hoffman, Catherine Keener, Christopher Walken and Mark Ivanir to the film, which follows a New York string quartet whose future hangs in the balance as they prepare for their 25th anniversary concert.

“I was interested in making an intense family drama in a new setting,” says Zilberman, whose only previous film credit is 2004 documentary “Watermarks.” “I thought the dynamic of a string quartet, the co-dependency of that unique formation of people who work together for 20 years, traveling seven months of the year, could be ideal.”

Keener was first to board the project, sticking with it two years before it was ready to shoot, a “major turning point” for Zilberman. Then came Walken. “It’s not a typical Walken role,” admits Zilberman, but he and the actor connected over their love of the music. “Chris invited me to his place and we sat and listened to classical music together.”

Hoffman’s involvement arose after Zilberman attended a recital of the Takacs Quartet (whose one women and three men composition was an inspiration for the movie’s quartet) at Carnegie Hall. Hoffman accompanied the musicians onstage to read excerpts from Phillip Roth’s “Everyman” in between the music. “It was so moving how he read the pieces and how it connected to the music. The whole world was very dear to him,” says Zilberman.

Zilberman’s meticulous research developing the script over three years proved the big draw for each actor. The director approached the Attacca Quartet to document their learning Beethoven’s String Quartet number 14, Opus 131, which became the centerpiece of the movie. “It gave me the chance to really know this world on an intimate level, to learn how they talk about the music between themselves.” He then approached the Brentano String Quartet to play the piece for the movie, which he documentated and used to create a video board so his actors could choose from five different angles to see how the musicians played in order to achieve the right look on camera.

The composer proved the hardest team member to choose. “We had Beethoven’s Opus 131 as the centerpiece so there was a problem of what music can you add?” says Zilberman. Listening to Angelo Badalamenti’s music while doing research he knew he’d found his man. “It has beauty with an aspect of pain,” explains Zilberman. “I also wanted a composer with stature within film music and Angelo has that gravitas.” Badalamenti came up with the concept of using a wind quintet so his music would work around the existing music and not compete with the string quartet.Zilberman didn’t always appear destined for movies, studying physics and a masters in operations research at M.I.T. before taking a job on Wall Street. “I fluctuated between becoming an artist or something more practical. Filmmaking can address both aspects, the art and creation alongside business and collaboration.”