À mon chevet is a series of posts featuring a quote from whatever book is on my nightstand at the moment.
The outer events of Tristan und Isolde and Pelléas et Mélisande are far from dissimilar -- or, to put it differently, the two love-affairs whose progress they relate would appear much of a muchness in a divorce-court. [...] But it is necessary to distinguish sharply between Plot, meaning the outward paraphernalia of events, and Subject -- the interior exposition of the heart of the matter. I have outlined the mere plot, in its Tristan and Pelléas version; but the differences of emphasis in the two works render this similarity surprisingly unobtrusive. For the subject of Tristan und Isolde is Passion, or rather, as Mann put it, 'sensuality, enormous sensuality ... sensuality unquenchable by any amount of gratification'. Whereas the subject of Pelléas et Mélisande is loneliness, lack of connection -- in the end a frigid nihilism. This fundamental difference in the two treatments of virtually the same plot, must always be borne in mind during the following account of the correspondences between the two works.A friend reminded me of this book recently, when we spoke about a new book on the sopranos who created the role of Mélisande (review forthcoming), and then lent me his copy. It was a doctoral thesis in the 1970s, published shortly after by Ernst Eulenburg, that examines Debussy's appropriation, either conscious or unconscious, of Wagnerian harmonic and orchestrational structures in his works. Far from being strictly an anti-Wagnerian opera, Pelléas actually has a lot in common with the Wagner operas that Debussy particularly admired, Tristan and Parsifal. The case laid out in Holloway's music examples is pretty much water-tight. More to come.
Both operas subsist in a kind of social void. Constant Lambert once remarked that comparison of the off-stage sailors' choruses in the first acts of Tristan and Pelléas provided a microcosm of their respective composers' mannerisms. In the former they sing vigorous anti-Irish songs in a four-square Meistersinger-Guild style, in the latter they are restricted to mysterious cries of 'hisse-hoé, hisse-hoé'. These choruses could also stand for the way in which, in both operas, the world at large remains as it were off-stage. This is exceptional in Wagner, all of whose other operas concern themselves with a wide range of relationships, whether social, familial, psychological, or ritualized.
-- Robin Holloway, Debussy and Wagner, pp. 60-61