It's largely a tribute to the original Broadway musical of Fiorello!, done on the old Kraft Music Hall with Perry Como, in November, 1961. It features the then-unknown Tom Bosley who came to fame starring as LaGuardia in Bock and Harnick's musical. And for this surprisingly long sequence, he and Como talk about Fiorello as Bosley makes himself up for the role, there's then a bizarrely long montage of newsreel footage of LaGuardia, to help explain who he was, Bosley sings a song from the show, and then (in the clip I'd previously posted) he appears as "sort of" Fiorello in a comedy sketch, imagining what LaGuardia would be like today -- which ends with another song from the show!
(Fun too is that the sketch includes the Kraft Players, among them Paul Lynde and Kaye Ballard. Making this all the more odd, though, assuming the November, 1961, date is correct, is that Lynde's big break came in Bye Bye Birdie which opened the previous year. And Ballard's came with the musical Carnival which opened seven months before this appearance. But there they are on the Kraft Music Hall doing sketch comedy.)
What even more odd about this -- beyond the time spent on the show and having a long film clip section -- is that I think Fiorello! had closed by this time. But Bosley did take the show on the road, so maybe it was done in conjunction with that. Regardless, it's a rare joy to have.