That’s a good explanation and a useful metric. Dates get messy and the willingness of composers to get experimental AND intentionally dismiss popularity as meaningful is key.
After all … Beethoven was highly experimental when it came to form and phrasing and he even touched on atonality in his “Grosse Fuge” https://en.m.wikipedia.org/wiki/Große_Fuge but he was desperate to publish and though pushing limits, worked tirelessly to be popular.
Then there is Charles Ives: an American insurance salesman from the 1800’s who wrote highly experimental music and was almost completely unknown until his music was discovered 50 years later. Let’s just call him a notable exception… date wise. BUT! Check this out.
How does that even exist in 1906? Oh well … so he is an Exception and an Enigma (pun intended!)
So back to defining “Contemporary Classical”… yes … I like WW II-ish; that certainly is about the time audiences started to catch on and listen. DONE!
Then there is the term “Classical” … technically the “Classical Period” covers mid 1700 to mid 1800: but I believe the intent of this thread is referring to European style Academic as opposed to popular, folk, or other music.
This is going to be a great thread! Thank you @Lug for elevating us!