Although its decade-long existence was one of artistic and financial uncertainty, the Paris-based ‘Domaine musical’ was important in promoting radical new music at a time of apathy, even hostility in establishment circles. Its recordings have previously appeared on long-deleted anthologies, making the appearance of these two Accord sets the more welcome.

Then in the throes of his love-hate relationship with Schoenberg, Pierre Boulez directs pugnacious accounts of the Serenade and Suite and a high-pressure First Chamber Symphony. An intense Verklärte Nacht is still among the finest, and if Pierrot lunaire can yield more expressive light and shade, the recitation of Helga Pilarczyk has lost little in immediacy. Webern was of especial importance to Boulez at this time: performances of the Symphony and Cantatas have an eloquent poise, while Yvonne Loriod maps out emotional tension in the Variations with an unerring rightness and largely eschews rhetoric in Berg’s Sonata. Stravinsky was hardly in need of such promotion – but Boulez evinces affection for the Concertino and Symphonies of Wind Instruments, and a Renard whose theatricality is unsurprising given his years spent with the Renaud-Barrault company.

The other set focuses on Boulez and his contemporaries, along with Messiaen – the tentative premiere of Oiseaux exotiques and a first outing for the iridescent Sept Haïkaï – and Varèse, an explosive Hyperprism and a seething Intégrales. The intricacies of Stockhausen’s Kontrapunkte now seem contrived but the pungent timbral interplay of Zeitmasze still compels – as does David Tudor in the convolutions of Klavierstück VI. Characterful works by Pousseur illumine a now-neglected figure, while those by Berio, Kagel and Nono are among the best of their era. Boulez is represented by grimly determined accounts of the Flute Sonatina and Structures I and by Loriod’s formidable Second Sonata – galvanising its violent contrasts with a sweeping intensity. Boulez’s second recording of Le marteau sans maître (in the main set) remains his most cohesive but his first account (on the bonus disc) is of inestimable value in enabling this seminal work to take shape, albeit falteringly, before one’s ears.

Remastering has, for the most part, been sensitively carried out (with no disguising the often primitive sound quality), and Claude Samuel’s booklet-notes are as penetrating as expected from ‘one who was there’. The bonus disc with Volume 1 also features Samuel in an extended interview with Boulez – on typically combative form as he plays down past successes while acknowledging the significance of what was achieved in those heady if fraught years.