As you would expect from BBC period drama, the Cazalets is an excellent production. Acting, casting, direction, décor, period detail, etc are all first class. I have not read the source novels by Elizabeth Jane Howard, but I am assured by those who have that the adaptation is also first class and conveys the spirit of the books throughout. But .. (and this is a major flaw, in my opinion) the drama is often ruined by intrusive, hackneyed background music. Tinkling pianos and lush strings are forever intruding on the drama as if to emphasise the soap opera dimension of the narrative. It is as if someone in the production team though that the audience would need a lot of emotive prodding to get the point in various scenes. What a blunder! The scenes which have no background music play well as straightforward drama and fortunately there are lots of them. It is a pity that someone decided to pour sugary custard over so many other scenes. And that is how a five star drama ends up as three star.
This semi-autobiographical story of a middle-class family's joys and tribulations in the run-up to WWII and its first years is generally well-made, with good acting. The period settings are mostly accurate, although it must be said that the attempts at seasonaility are poor: half-hearted artificial snow on full-leaved trees, birds still tweeting loudly in what is meant to be the depth of winter, and so on. But the interaction of characters is believable; some of them are a lot more pleasant than others. Working out all the relationships is a bit of a challenge in the first hour, so close attention is needed. The ending is a bit abrupt. Amongst a large cast, Ursula Howells, Emma Griffiths Malin and Hugh Bonneville stand out; Frederick Treves makes an irritating but probably accurate obsessive old man.