Premise: Revisited is a 1960 album by Tom Lehrer, consisting of live recordings of all the songs from 1953's "Songs by Tom Lehrer". The CD reissue of the album contains two additional tracks that Lehrer wrote and performed for the PBS television show "The Electric Company" (and produced and conducted by Joe Raposo).
Hypothesis: Tom Lehrer included two extra songs from a PBS TV show into his Revisited album