The shriek on The Wall, was lifted from "Careful With That Axe Eugene", shrieking has been Waters' forte since the early days of PF.
To me, the park sounds in School (given it’s precedence) sort of spark/reinforce a theme similarity between the two albums that is kind of hard to deny.
I like Floyd and bought The Wall the day the album was released. I will honestly say that other than radio, I haven’t listened to them in 30 years.
I listen to Supertramp all the time though. The fact that they aren’t in the rrhof is a ridiculous joke.
Actually, I think he was more referring to the natural playground shrieks rather than the the singular shriek which bridges from The Happiest Days of Our Lives to Another Brick in the Wall. But Pink Floyd was also VERY into Musique Concret, the use of natural sounds in music. There are entire “songs” featuring nothing but Musique Concret on their earlier, experimental albums. So I gotta call the playground shrieks, “inevitable discovery.”
OTOH, there’s a syncopation and brightness on Another Brick in the Wall, Pt 2 that’s wholly alien to Pink Floyd (it was actually imposed on them by their producer, Bob Ezrin) that sounds a lot like School.
Even the themes aren’t as similar as you might suppose: School is about the failure of schools to teach real life, amidst an album about how unfair Britain’s class rigidity is; Another Brick pts 1 and 2 are part of a “backstory” suite of songs that explain how Roger’s/Syd’s/Pink’s abuse at the hands of oppressive schoolmasters led to his emotional problems.