@larryi
Great Question.
I have submitted only 'greatest hits' pieces, as defined by enduring popularity and critical acclaim for music that is over, say 100 years old. This lens ensures durability and avoids transient hits (for better or worse).
This includes the "Late Romantic Period" (Tchaikovsky, Mahler, Debussy, Dvorak, Elgar, Sibelius, Rachmaninoff, Strauss, Ravel, etc.) and marches back to the very earliest written music...
Of course a strong case can be made for The Rite of Spring, Firebird, Rhapsody in Blue, etc., but I wonder if they will still be popular in 20 years now that streaming has opened Pandora's Box (i.e. too much content to develop a consciences).
That being said, I would recommend them to anyone, as they appear to endure.
Finally, my goal is simply to get a 'starter list' of great classical compositions and recordings for anyone willing to spend their time exploring the genre, with no hard rules...