For composer Thierry Pécou, planning concerts for his group Ensemble Variances is about more than juxtaposing pieces that sound well together. There needs to be an over-arching theme, something about the choice of works that connects with the wider world beyond the music itself. For their Wigmore appearance, the ensemble’s programme had several interweaving themes – there were connections with myth and legend, epitomised by a chamber arrangement of Debussy’s Prélude à l’Après-Midi d’un Faune and Szymanowski’s violin-and-piano Myths; the sea, in Takemitsu’s Toward the Sea III; and above all, the harder to define connections between the creativity of humans and that found in the natural world, as investigated in pieces by François-Bernard Mâche and Pécou himself.

There were parallels too between the techniques used in Mâche’s Sopiana and Pécou’s Méditation sur la Fin de l’Espèce, which was a Wigmore Hall commission. In Mâche’s 1980 piece, flute and piano play together with recordings of three birds, a Malaysian shama and two European warblers, creating sequences of solos, duets and trios that find an equivalence between the instrumental virtuosity of the players (Anne Cartel and Marie Vermeulin in this dazzling performance) and the inexhaustible inventiveness of the birdsong.

Pécou’s work extends the same techniques to a solo cello and a larger ensemble, and to the even more evocative world of whales. The cello, played by the indefatigable Anssi Karttunen, acts as a mediator between the ensemble and the deep-sea sounds – the clicks of sperm whales, the “songs” of humpbacks, and at the very end of the piece, the whistles of a beluga – and the results are strikingly beautiful, sometimes discomfiting, and in the end profoundly elegiac.