Brian Elias has a packed schedule this year — and that is a bigger statement than it sounds. An elusive composer, now 68, who lives quietly in Golders Green, he has never been prolific. Yet now his star is in the ascendant. This autumn, his score for The Judas Tree returns to the Royal Ballet; the last ballet choreographed by Kenneth MacMillan, it was premiered 25 years ago. Before that, a cello concerto is due for its first airing. A new CD of his works is released this spring on the NMC label. And next week at the Wigmore Hall, the oboist Nicholas Daniel and the Britten Sinfonia premiere his new Oboe Quintet.

Why so few pieces? Partly, Elias suggests, because he is convinced music needs a real, urgent purpose behind it. This realisation, he says, was a breakthrough when he wrote L’Eylah (premiered at the Proms in 1984), paying tribute to his sister, who had died tragically of a drugs overdose. The title is a quotation from the Kaddish. “I became conscious that a piece has to have a reason for its existence and that it should be written out of real need, not simply to fill up paper or to fulfil a commission,” says Elias. L’Eylah was also the first occasion on which his music drew on his unusual Iraqi Jewish Indian background: “A solo viola quotes an Iraqi Jewish love song that our grandmother used to sing to us as a lullaby.”

He was born in Bombay and in childhood absorbed a rich soundworld from the surrounding melting pot of Indian street music, different languages and colourful dialects. He began trying to compose as soon as he started piano lessons, aged seven, “but it was only when I was sent to school in England that people really began to encourage me,” he says.

Later, having experienced disappointments at the Royal College of Music (“my teacher was usually drunk”) and Cambridge, which ended with a nervous breakdown, he took private lessons with the composer Elizabeth Lutyens, whom he met at the Dartington International Summer School of Music and who provided the intense, practical guidance he needed. “My first lesson with her lasted five hours,” he remembers, “as she showed me how to lay out an orchestral score properly.”

Successful broadcasts of his early works on BBC Radio 3 attracted the interest of the publisher Chester Music, and Elias found himself in a strong position that enabled him to pick his projects. One of his greatest successes, Five Songs to Poems by Irina Ratushinskaya, was premiered at the Proms in 1989 and led directly to MacMillan commissioning The Judas Tree – “My jaw absolutely hit the floor,” Elias remembers.

While the Ratushinskaya Songs and The Judas Tree dealt with harrowing emotions, Elias’s use of Jewish ideas has been altogether gentler. Besides L’Eylah, he wrote a piece for the unlikely mix of soprano and hurdy-gurdy based on The Song of Solomon, and in 2004, A Talisman, a setting of Hebrew texts for bass-baritone and chamber orchestra. “Among my mother’s things after she died I found a talisman, an Iraqi Jewish mid-19th-century piece of silver full of inscriptions,” he says. “I was intrigued and wanted to find out more.” A professor from Jerusalem University helped to identify its content, which included quotations from the Psalms, mysterious Kabbalistic phrases and the beginning of the First Book of Moses. This work is on the new NMC release.

Usually, though, Elias’s music is abstract. “I’ve always written very organically,” he says, “and very instinctually. My need to communicate is greater than my need to push instrumentalists to extremes, so I only use extended techniques if it’s necessary for expressive purposes.” The pared-down purity of approach is perhaps reflected in the fact that when Nicholas Daniel asked for an oboe quintet, Elias suggested a quartet instead, “because what on earth do you do with the second violin?”

The result — a quintet after all — has delighted the oboist. “Brian’s work is beautifully wrought,” Daniel says. “The arguments he makes inside the piece are fierce and intellectual, yet it’s pure music with no stated narrative. It has a particularly strong line, while retaining a beautiful ear for colour. I’m especially proud to play it as Brian only writes about one work a year. I consider him one of British music’s greatest treasures.”

Brian Elias’s Oboe Quintet is at the Wigmore Hall on 19 April at 1pm. Box office: 020 7935 2141