Estonia’s best-known internationally orientated modernist has composed six symphonies (the latest having had its premiere earlier this year in Tallinn), among which the 30‑minute single-movement Fourth, dating from 2002 and subtitled Magma, is outstanding. Tüür’s style is essentially mobile-sculptural: which is to say that shifting sound-masses count for more than expressivity. Sibelius is a distant yet clear affinity, and Lutoslawski and the sonorism of the Polish school of the 1960s and ’70s supply something of the technical means. At its gentlest – as in the tinkling early stages of Magma – the effect resembles Oliver Knussen; at its toughest, Elliott Carter. Impersonal yet irresistible forces seem to guide the structure, while the orchestra builds up a succession of analogies to unpopulated landscapes and natural forces. Behind the sonic richness and the dazzling surfaces there is an ascetic instinct at work: a refusal to take easy, opportunistic paths and an immensely impressive traversal of craggier ones.

Though written for Evelyn Glennie, who takes the solo percussion part with superb aplomb, this really is a symphony rather than a flashy, beefed-up concerto. It stays just on that side of the divide everywhere except in the brief cadenza at approximately the half-way mark.

The other three works on this disc feel similarly substantial and born of inner necessity. The Path and the Traces is simply the finest recently composed piece I have heard for string orchestra, and each of the choral items is memorable, without sacrificing complexity. Tüür is currently well represented on CD, but this new disc strikes me as probably the most rewarding devoted to his music, no doubt partly because performances and recordings are first-class. If the prospect of challenging, granite-hewn musical invention has any appeal, then this is a must.