One of the few really good programmes on Radio 4, along with Inside Science, Last Word, and The Moral Maze. Tracks (a long sci-fi drama) was also good, with appropriately atmospheric music- usually I find the music irritating (other than in music programmes obviously!) Although the ending of the whole series felt implausibly neat to me.
It's amazing how Melvyn Bragg gets his head around such a diversity of subjects, totally different each week, and how he manages to prevent his academic guests from waffling and wasting time and gets them to explain things comprehensibly to the non-specialist listener. He's 81 by the way.