Harris's book must have been really ancient history by the time you got to it! I read it in 1957 at the age of 17 and spent a few months as a "jazz purist". His extraordinary message seemed to be that if a band hadn't got a banjo in it, it was no longer jazz and that Ellington ceased to play jazz when he added saxophones in the late 20s!!! Fortunately, Bird, Diz, Monk and Miles blasted me out of that way of thinking when I was 18.
I think Charlie Parker got about half a paragraph in that book. Fortunately, I cottoned onto the omission pretty quickly.
I read Philip Larkin's tome not long afterwards and amazingly came out of it all pretty undamaged !
There was a big difference between the standard of academic teaching between the Catholic and non-Catholic places. Basically, the feeling was that you didn't have much chance of ever progressing to University and beyond with the former.