This is one of the increasingly distinguished series of 'Introduction to ...' CDs that have come out on the Naxos label. And I particularly like it because not only is the narration written by Thomson Smillie smart and clear, it also is much broader than one would expect. This is not just 'the story and the music.' The text also sets the historical and cultural context in which 'Pelléas et Mélisande' came to be written, and he traces the debt he owes to Wagner, a point often glossed over. The voice-over is done by actor David Timson who not only has a sonorous reading voice but also an excellent French accent.
As with all these educational CDs the musical examples - and there are tons of them, and not just from the opera itself - are taken from the extensive Naxos back-catalog. I have not heard their full recording of 'Pelléas et Mélisande' (conducted by Jean-Claude Casadesus, and featuring all French singers) but on the basis of the excerpts I think I'll have to seek it out.
Strongly recommended, even for those who think they already know 'Pelléas.'