The most significant musical anniversaries of 2018 are all centenaries – of the births of Leonard Bernstein and Bernd Alois Zimmermann, and of the death of Claude Debussy, and it’s the last of those, which falls in March, that is attracting the attention of record companies. Warner Classics has got in early with its 33-disc set that aims to include everything Debussy wrote, from his earliest songs of 1879-80 to the three sonatas composed during the first world war, as well as his own transcriptions, and arrangements of his music made by others during his lifetime.

Presented chronologically within each genre, it’s a scrupulously assembled and documented collection, with the bulk of the material sourced from within the Warner group – performances that first appeared on EMI, Erato or Virgin Classics – but also borrowing from other labels for some of the rarities, as well as including a handful of minor pieces recorded  for the first time.

There’s also a final disc of Debussy’s own performances from piano rolls and 78s, playing some of his Préludes and the Children’s Corner suite, and accompanying Mary Garden in the Verlaine settings of Ariettes Oubliées and an aria from Pelléas et Mélisande.

Prelude “Afternoon rest of the Faun” was written on the basis of the poem by Stephen Mallarme in 1892. The work of Mallarme attracted the composer in the first place to the vivid pictoriality of a mythological creature, dreaming of a beautiful nymph on a hot day.

In prelude, as in the poem by Mallarme, there is no developed plot, a dynamic development of the action. At the heart of the work lies, in essence, one melodic image of “languor”, built on “creeping” chromatic intonations. Debussy uses for his orchestral embodiment almost all the time the same specific instrumental timbre – a flute in a low register:

As a reference source it is invaluable, especially for tracking down some of the early songs or more obscure fragments of orchestral music, but the main problem with any collection of this all-encompassing kind is unevenness. The recordings of the composer himself apart, the performances range across more than 60 years – with a lot of the songs in particular dating from the 1970s – and their quality, along with that of the recordings, can be variable and sometimes rather disappointing. There are certainly more convincing performances of many of the piano works to be found elsewhere, while Carlo Maria Giulini’s rather staid renditions of La Mer and the Nocturnes with the Philharmonia Orchestra, for instance, don’t stand up against the best current versions.