When you are the architect of the musical accompaniment to people's fondest movie memories, it can be hard to choose your finest moment. One of the best-known film composers of our time, Howard Shore has certainly been around the proverbial block – from Middle Earth to Philadelphia , negotiating Gangs of New York , Single White Female and She-Devil in the process – but coaxing him to name a favourite is like asking him to choose one child over another.

Shore was born in Toronto in 1946, and his interest in music and theatre took root from a young age. At nine, he had taken lessons in harmony and counterpoint to complement his studies in woodwind. During his college years at Berklee School of Music, classical began to take a back seat as he became interested in jazz. He played in fusion band Lighthouse and musicians such as Ornette Coleman became strong early influences.

Having initially written for small chamber groups, his dabblings on documentary films eventually led to work in radio and television. Childhood friend Lorne Michaels, the writer, producer and creator of Saturday Night Live , gave him his big break in TV, which eventually led to a five-year stretch as musical director of SNL in the mid to late 1970s.

In 1979, his first foray into film scoring came in the form of David Cronenberg's The Brood . The collaboration kick-started a bond that endures to this day; Shore recently scored his fellow Canuck's upcoming film Maps to the Stars .

"I wrote The Brood for 21 strings, and it was really the first time that I'd had a small string orchestra in the studio," he says. "[Cronenberg] allowed me a lot of creative freedom, and we've done 15 films since then. I've known David since I was quite young, actually – he's a little older than me, but we grew up in the same neighbourhood, so we both have a similar outlook on things like what film can be, and what you can do with film, and how to use film to tell different types of stories, whether narrative or non-narrative. He's a director who tries a lot of different things and is very creative. He's always a few steps ahead of everyone intellectually; he's probably the most well-read person I know. So keeping up with him is always a challenge."

An eclectic filmography
Nothing if not eclectic, Shore has over the past three decades collaborated with some of the most celebrated directors of the modern cinema age, including Martin Scorsese and David Fincher. He has written scores to films about teenage vampires ( Twilight ), serial killers ( Silence of the Lambs ) and cross-dressing nannies ( Mrs Doubtfire ). He credits his versatility to his early forays into theatre – directing, acting and writing alike.

“In the younger part of my career, I did a lot of repertory theatre, and a lot of the work that I did in radio and television was also repertory,” he says. “So significantly different stories always felt very natural to me: it was comedy one night, tragedy the next. It felt very natural to move between those styles, and that’s something I brought into my work in films.”

Shore's work with Peter Jackson on the Lord of the Rings trilogy is undoubtedly his best-known, and also his most celebrated: he has won three Academy Awards for the trilogy, several Golden Globes and a variety of other honours. He had never tackled a job of such epic proportions before. How did he feel when first approached by Jackson?

“Was I daunted? I think anybody would be daunted by it,” he says, chuckling. “It’s one of the great novels of the 20th century and probably the most complex fantasy world ever created. I spent almost four years creating the piece, and I worked at it step by step, day by day. I had good collaborators, and I just slowly started in the Mines of Moria and I worked my way forward through Lothlorién. I just held a lantern up in the dark and kind of went one step at a time and tried to connect pieces.

“I didn’t have a huge grand plan, because it was too massive an undertaking, so I did it in sections and then connected the parts and the stories together. When I studied Tolkien’s work from Marquette University and saw his notes from the trilogy, I found that he wrote in somewhat the same way. He was finding his way on a path and studying different phases of the moon and the mines of King Thorin and he connected the stories together. So we were all finding our way, in a certain sense.”

Once he had committed to composing for the trilogy, he went back to the source material for inspiration. “I like to read a lot, so I always go back to the source from the film, whatever I’m working on,” he says. “I do a lot of writing from the ideas inherent in the story; there’s a lot of free association to the story and to the musical composition. It’s a way for me to express my ideas on the piece, and it’s generally away from the film and the imagery. Then I go through another lengthy process of applying what I’ve created with themes and motifs; the underlying subtext of the story that I’ve worked on separately. I’ll apply that to the film specifically, scene by scene, in what I call the ‘scoring process’, and then I orchestrate that music and I perform it and conduct and produce it in the studio.”

His forthcoming Dublin concert will showcase several pieces from The Return of the King , but will also exhibit his non-film work, including the Irish premiere of three pieces written for cello, for chamber orchestra and a Fanfare for Organ and Brass. Having completed work on the final film i n the Hobbit trilogy, his current work schedule includes a second opera "in the early stages" (his first, The Fly – loosely based on Cronenberg's film – premiered in 2008) and a chamber piece for La Jolla Festival.

So why focus on The Return of the King ? He describes it as "the culmination of all of my work at that point in my life". Is that finally a tentative admission of favouritism?

"Well, the music from the Lord of the Rings trilogy was really a combination of everything I had learned at that point, about music and about symphonic writing, choral music, orchestration, recording," he says, smiling. "But there's a lot more to do. I'm proud of it all. I enjoy it all."

Howard Shore will present an RT É Concert Orchestra performance of his work at the National Concert Hall, Dublin, on Saturday