Debussy andsymbolism:

the opera Pelléas et Mélisande based on a libretto by Maurice Maeterlinck

Concept Map of the libretto JPG

Vocal score PDF

Orchestral score PDF

Opera Guide PDF

Maurice Maeterlinck (wikipedia-artcle)

Prologue LotR (youtube)

Libretto F-En PDF

Esa Peka Salonen about P&M

Simon Rattle about P&M

Pelléas et Mélisande explained (Spotify) by David Timson, an introductory lecture with musical fragments.