She has been dubbed the high priestess of sado-minimalism, the lady with the hammer and the bearer of the pure gospel message. Critical opinion is divided on the singular achievement of G. I. Ustvolskaya, whose music has found a special — and likely enduring — niche in the Western world only since the dissolution of Soviet communism.

Indeed, perestroika heralded quite a bombardment of hitherto marginalised, often faith-inspired composing talent, sometimes allied to a painful human interest story. High-profile examples include Pärt, Gubaidulina, Kancheli, Schnittke and, as Robin Holloway somewhat sardonically put it, “Ustvolskaya and her coffin box”. The “coffin box” was in fact the homemade plywood cube which features prominently in several of the bizarrely scored compositions of her late maturity.

Until then Ustvolskaya was perhaps known to Russophiles as a footnote to the still ongoing, overheated saga of D. D. Shostakovich. For the best part of a decade she was his pupil at the Leningrad Conservatory, with the older composer quoting from the younger in at least two of his works, making gifts of his manuscripts to her and declaring that it was he who learnt from her and not vice versa. Rostropovich observed “a very tender relationship” between the two, and in a rare interview she herself alluded to a marriage proposal. But whether the association extended to any fuller intimacy remains a moot point, and with both composers now dead the truth may never be revealed.

Her music too was scarcely better known. Apart from the succèss d’estime of a not inconsiderable quantity of robustly Soviet-themed pieces, with stirring titles such as Young Pioneers, Dawn Over the Fatherland, and Lights of the Steppes, obviously written to keep the wolf — and worse — from the door and latterly expunged from her catalogue, her “formalist” music — particularly the extraordinarily intense and introspective works of the 1970s and 80s — was, it seems, scarcely played even in her own country, let alone abroad. Her first performances in the West were probably at the Wiener Festwochen in 1986, with further outings following in Hamburg (1988), Huddersfield (1992) and, with the composer present, Amsterdam (1996).

Since then her music has been recorded with increasing frequency. Her mature output revolves around four of five symphonies and two of six piano sonatas, the former appended with religious subtitles – True and Eternal Bliss, Jesus Messiah, Save Us!, Prayer, and Amen. Scored unconventionally for chamber forces, terse to the point of rudeness yet monolithic in scale, and in three cases setting texts by the disabled, medieval ascetic Hermanus Contractus (Herman the Cripple), they explore experience at the edge, where hope has been abandoned. A similar world is inhabited by her fifth and sixth piano sonatas, in which clusters and extreme dynamics are as omnipresent as the scraps of conventional keyboard writing, and by her three numbered compositions: no.1, Dona nobis pacem for piccolo, tuba, piano; no.2, Dies irae for eight double basses, percussion, thick plywood cube with wooden hammers, piano; and no.3, Benedictus, qui venit for four flutes, four bassons and piano.

For someone who lived her entire life in Petrograd/Leningrad/St Petersburg during the most difficult days of its history, biographical facts are hard to come by. She was born in 1919; studied between 1937 and 1947, with a wartime intermission as a hospital orderly; and married Konstantin Makukhin in 1966. After her retirement in 1977 from 30 years’ teaching at the Leningrad Conservatoire, she cultivated the image of the high-principled, reclusive curmudgeon, who seldom ventured outside her apartment, rarely gave interviews, was painfully photophobic, and declined to contribute her memories of her teacher to Elizabeth Wilson’s sourcebook Shostakovich Remembered.

Some have been sceptical of her much-advertised religious convictions, but it may be that by the time of her greatest achievements a superficial show of conventional piety would have seemed as false as any former public commitment to atheistic communism. When success came, she distanced herself from Shostakovich, stressing her own uniqueness. But whatever her perspective on her own history, her music burns with the pure fire of truth, with a focus and intensity that eluded even her spurned mentor.

Her final work was the Symphony no.5, completed in 1990, a 12-minute setting of the universal Christian prayer, the Our Father, recited in Russian over a characteristically grim processional of oboe imprecations, tuba growls, and the ominous thud of the “coffin box”.

Galina Ustvolskaya, composer, was born on June 17, 1919. She died on December 22, 2006, aged 87