His may be an unfamiliar name but the Swiss composer René Wohlhauser (b1954) has gained a wide reputation for his sizeable catalogue these past four decades, while being equally active as baritone, pianist and director. All of which are put to distinctive use in the present work, a chamber opera derived from texts by Jean Paul Sartre and Simone de Beauvoir. Or it would have been had not the former’s estate withheld permission, leading Wohlhauser to replace them with ‘sound poetry’ whose phonetics replicate the expressive content of Sartre’s texts.

Other than Sartre’s early treatise L’être et le néant, these texts (actual or intended) are letters exchanged over the period January 5 – February 23, 1940, when Sartre and de Beauvoir became engrossed in a sexual relationship as much about those others involved as themselves. This is enacted across a prologue and three parts, soprano and baritone partnered by an ensemble resembling that of Pierrot lunaire (but without violin), the manner which they merge into – even become – each other defining the essence of this piece as much as any purely semantic evolution. This is most evident in the second part, much the longest yet having the least text, in which voices and instruments lock into passages of melodic and rhythmic unison charged with an emotional intensity though also a confiding intimacy affecting in its tangible poise.

The performance, recorded in the studio following two European tours, sounds as focused and involving as expected given the lengthy collaboration between the composer and the Basel-based Ensemble Polysono. Christine Simolka makes a suitably alluring contribution, with Wohlhauser as committed vocally as in the sparing yet strategic piano part. It makes for an intriguing and provocative experience. One looks forward, moreover, to the stage premiere in 2051!