Only three years separate the first sketches of Arnold Schoenberg's only symphonic poem Pelleas und Melisande, Op. 5 from the string sextet Verklärte Nacht of 1899; yet in some ways the distance traveled during this brief span is greater than that traveled by many composers during an entire lifetime. While the musical roots of Pelleas are, by and large, the same as those of the sextet -- the most immediate being debts to the underlying "Leitmotiv" techniques of Wagner and the surface-level luxuriousness of Richard Strauss' own tone-poems -- the contrapuntal web that Schoenberg weaves in Pelleas is so dense and of such chromatic complexity that the music is transfigured into something wholly new. To be sure, Pelleas is not an entirely successful score: the manner in which tonal and hyper-chromatic idioms interact throughout the score is perhaps not as fluid and natural as it had been in Verklärte Nacht, and the piece sometimes runs the risk of collapsing under its own weight. But during the early twentieth century, Schoenberg's musical language was developing at so rapid a pace that he could scarcely keep up with himself, and it is entirely understandable that, in his effort to give birth to such a remarkably new style of musical expression, he would overstretch himself a bit; before the decade was out, the path to which Pelleas clearly points had been followed, with consequences that would shape an entire century of music.
In 1902, Debussy's opera based on Materlinck's Pelleas and Melisande was hot off the press; Schoenberg, however, had no knowledge whatsoever of the French composer's effort, and proceeded to plan his own opera after the play. He rapidly discarded this plan in favor of a purely instrumental study of the work, feeling that his emerging style would be better served if the music were allowed to shape its own course in a way that a strictly text-derived work could never do. The rich scoring of Pelleas reflects the same late Romantic tendency towards inflation that marks the nearly contemporaneous scoring of Gurrelieder: 17 woodwind players, 18 brass, more than a half dozen percussionists, and a reinforced contingent of strings and harps are all on call. Pelleas und Melisande is cast as a single large body of music, in which the four traditional symphonic movements are still vaguely discernable, but which puts more stress on the myriad structural and expressive possibilities that result from juxtaposing several levels of motivic detail than on the well-worn shadows of "arbitrary" formal outlines.
And so, after the sober, chromatic melody that begins the narrative, we are offered a tragic theme representing the beautiful Melisande and an energetic, soaring Pelleas theme. Like Verklärte Nacht, Pelleas draws a large-scale D minor tonality; on the local scale, however, it is even more chromatically far-flung. From time to time, more conventionally "Romantic" passages crop up, such as the love scene that appears as a kind of adagio movement. The epilogue, in which Schoenberg reflects on the death of Melisande, is a masterstroke, as is the final, resigned descent back into D minor.