"In Our Time" is my favorite podcast.
The show is a brisk 40-45 minute discussion on all manner of subjects: history, art, literature, and science. The host is Melvyn Bragg, a British writer/broadcaster with a firm grasp of whatever the subject happens to be. His guests are three academic specialists in the subject matter: a panel of articulate scholars.
When I first learned about this podcast, I picked out the subjects that were of interest to me: engineering, science and math. As I grew familiar with show and its format, I found that Melvyn's manner made any subject seem vibrant. He could produce an almost urgent note in his guests. I've listened to many great talks about history (both popular and obscure), art, poetry and literature.
All the guests are steeped in their subject. Whereas Melvyn has broad taste and knowledge, his guests are at the proverbial deep end of the pool. Without exception the scholars are articulate about highly specialized knowledge, and their enthusiasm for their subject can be quite infectious.
Melvyn would surely be considered a Renaissance man: a person with diverse interests and talents. It's clear that he prepares a certain way before each show, and he is the one that dictates the pace and the angle of approach. He defers to his guests, but he makes it clear that it his show, and he keeps things lively and brisk.
Add this show to your podcast collection, and broaden your mind!