Unsuk Chin has asked to be interviewed in writing because her English, she said, isn't confident enough over the phone.

But when I open her email it reads in long, detailed prose, a meticulous account of her development from self-taught child to South Korea's greatest composer.

"I was born in 1961. That was after the Korean War and at that time South Korea was one of the poorest countries in the world. My first musical memory is of touching a piano when I was four years old. It was a magical moment for me."

Chin's father was a Presbyterian minister and bought an upright piano for his church services. "He taught me the very rudiments of reading music and playing piano. After a few years I started accompany the hymns in his church. It was like an exercise in harmony (in fact, it was my first encounter with Western tradition). They would call out 'hymn number so-and-so' and I would have to play. I was only eight or nine years old and it was stressful, but also very good practice. Sometimes, when people got a bit excited and went higher, I would have to play a halftone higher, transposing up, sometimes down-"

As a child Chin did her bit for the family's income by playing the piano at weddings and other events.

"It was a childhood that doesn't any longer exist in developed countries," she writes. "I dreamed of becoming a concert pianist, but that was out of the question as there was no chance for me to have a teacher. But I listened to music every day. I learned to read scores. It wasn't possible to buy recordings or scores but I borrowed them from other people and copied them out – Tchaikovsky's Sixth Symphony, for instance, in its entirety."

Looking back, Chin says she's not sure whether being self-taught at that age had a negative or positive lasting effect. "On the one hand I greatly regret there was no chance to have a proper musical education as a teenager – it would have saved me from many detours. On the other hand, it might be that limitations and obstacles sometimes stimulate the imagination."

And what an imagination hers is. Chin has described her scores as a reflection of her dreams; the dazzling colours she paints in music suggest vivid dreams at that. If you're new to Chin's music, a good place to start is Acrostic-Wordplay, the fairy tales for soprano and ensemble that shot her to recognition in the early 1990s. Or there's Šu, the kaleidoscopic concerto for sheng – a traditional Oriental wind instrument – that the Seoul Philharmonic performed at the International Festival last year. Or the Violin Concerto, which the Philharmonia Orchestra and Viviane Hagner perform at the Usher Hall next Thursday. This is the piece that won Chin a Grawemeyer Award in 2004, and which many consider to be her greatest achievement to date. The prize jury praised it as "a synthesis of glittering orchestration, rarefied sonorities, volatility of expression, musical puzzles and unexpected turns".

The Philharmonia's programme also includes Bruckner's Fourth Symphony, and Chin approves of the pairing. "Though Bruckner's music belongs to a completely different epoch, I regard him as an innovator whose works function very well in a contemporary context. Compared with Wagner or Brahms, two perfectionist contemporaries, his music has cracks and gaps he was really at odds with in the aesthetic premises of his time – but this 'imperfection' makes him a very interesting musical visionary."

After university in Seoul, Chin moved to Hamburg to study with Gyorgy Ligeti, whom she describes as "scathingly critical, but very self-critical, too". It was 1985 when she began her lessons. "He was already 62 and very famous but he had begun to question everything he had done before and, as it were, to start from scratch ... He found a successful third way between avant-garde and mere postmodernism, and his taste regarding music was refreshingly catholic: he studied everything, was interested in non-European musical cultures and knew the Western tradition, including mediaeval music, like the inside of his pocket. He could also read and analyse scores like none other. Our relationship was difficult, but I learned very much from his artistic personality and his music."

Chin has settled in Germany and describes her identity as "mixed".

"I am very interested in different cultures but my primary goal is not to pursue a mixture of East and West, nor to belong to any specific group. I simply try to compose my own music and to realise my own ideas in it. I don't think I belong anywhere in particular."

She does, however, remain deeply connected with South Korea, and since 2006 has been in charge of programming contemporary music for the Seoul Philharmonic. "What has been fun in programming the series is that I don't have to adhere to any artistic dogma," she writes. "No-one is there to tell us that we may not present this or that type of music.

"But a lot needs to be done. We have presented a great deal of Korean or even Asian premieres – including the Korean premieres of a great deal of music by Messiaen, Ligeti and Boulez.

"The orchestra is fantastic and committed, so even if my series is just a drop in the bucket I have confidence that it will help the contemporary music scene to improve."

Unsuk Chin's Violin Concerto is at the Usher Hall on August 30.