These 4 CDs cover the 4 major periods of classical music. CD 1 covers the pre-baroque period, CD 2 the baroque, CD 3 the classical period and CD 4 the 20th century. CD 1 is very hard-going and creates the impression that this is production is for a specialised audience. In fact I was so out of my depth with CD 1 that I very nearly shelved the 4 CDs altogether. You will not understand much of CD 1 unless you have a good musical background.
Overall, this production deserves to lose one star because the excerpts are too short and there are too few of them, especially where important musicological terms are introduced whose scope cannot be grasped without belabouring the point with examples. Of course the lives of composers are mightily interesting and - for laymen like myself - easy to follow. But biography takes up space and time that could've been put to better use to bring home important musical technicalities, like what are the modal (tonal, atonal) scales. These technicalities are merely glossed over. Finally, this review wouldn't be complete without mentioning the narrator's superb diction and clarity of expression.
P.S.: The low recording level is problematic for those who listen while commuting. This seems to be a problem with other Naxos CDs, not just musical ones. It could be a ploy to discourage conversion to mp3. This could backfire because this is the age of podcasts, not the age of sitting down to a dining-room CD player. Not to mention that some infotainment systems in cars have don't handle the WAV format well and require prior transfer to mp3 anyway.