Most songs today do not have enough content to be sad. Go back to 60s/70s... Ugh. To start, almost any song from The Carpenters, Bread... for specific songs:
“That’s the way I always heard it should be” Carly Simon
“Send in the Clowns” Judy Collins
Oh and, of course:
“I don’t like Mondays” Boomtown Rats
80s picked up quite a bit thanks to the synthesizer but a couple were out there:
“Dancing with Tears in my eyes” Ultravox
“Think of Laura” Christoper Cross
“Tears in Heaven”, now there’s one.