Rumon Gamba’s d’Indy series – this is the final instalment – has done much to illuminate the complexities surrounding one of fin de siècle music’s more controversial figures. D’Indy, like Wagner, was both progressive and reactionary, and our image of the forward-looking teacher – his pupils included Roussel, Albéniz, Varèse and Cole Porter – still squares uneasily with the reality of the right-wing anti-Dreyfusard ideologue, obsessed with ideas of national identity and ethnic superiority. Influential in his lifetime, his music has an eclectic, pivotal feel, overtly synthesising influences in order to explore new possibilities.

The main work here is Wallenstein, completed in 1879, a symphonic trilogy based on Schiller, usually described as a response to The Ring, which d’Indy heard at Bayreuth in 1876. A variant of Wagner’s sword motif characterises the titular hero, a treacherous army officer trapped Wotan-like in schemes of his own devising. Yet the melodic contours suggest the predominant influence of Berlioz; the cyclic form derives from Franck; and a weird chordal sequence depicting the superstitious Wallenstein’s astrological consultations startlingly prefigures the Nietzsche setting in Mahler’s Third Symphony.

Elsewhere, we find comparable links and overtones. The 1897 opera Fervaal is indebted to Parsifal, its Act 3 Prelude pivoting back to Klingsor’s incantations and forward to Pelléas. Suite dans le style ancien is not so much a work of Rococo pastiche as an astringent intimation of 20th-century neo-classicism. The beautiful Lied for cello and orchestra invites comparisons with Massenet, a rival of whom d’Indy was not particularly fond.

Gamba’s conducting evinces the care and thought characteristic of the retrospective as a whole. There’s an admirable awareness of the crafted sensuousness of d’Indy’s textures, the slightly studied novelty of his compositional style. The Iceland Symphony Orchestra’s brass glare a bit, though the playing is judiciously honed. Cellist Bryndís Halla Gylfadóttir sounds very svelte in the Lied. D’Indy’s reabsorption into the mainstream is a questionable prospect at best. But the series forcefully reminds us of his achievement and importance.