There's a fairly new podcast (it started in Sept '21) called "Handed Down" which focuses on one song each podcast. The host, Jenny Shaw, is knowledgeable (and a lovely singer and multi-instrumentalist) and usually interviews someone about a song that has been "handed down" to them (sometimes she is solo).
So far the podcasts have been very interesting and entertaining. Songs covered thus far are: Flandyke Shore John Barleycorn Barbara Allen Old Pendle She Moved Through the Fair Death and the Lady The Brisk Lad The Christ Child Lullaby Pretty Saro Poor Boy
This link (same as the link above) "Handed Down" will take you to the list of episodes.