None.

Nothing that's a 'hit' in the modern day will have any of the staying power of say, Beethoven.

Even now, hits are dead within a few years. The average person is being conditioned to only 'consume' entertainment that has been recently released.

To hopefully drive this point home, notice how Weird Al parodies have more staying power than the songs he's parodying? Nobody thinks this will be the case when a song is new and the consumer bandwagon is being told to like it.

I'm sure people thought, say, something like SAIL would 'stand the test of time,' but it's actually cringe as fuck to listen to now. That's not going to change as time passes.

Notice how Elvis, the 'king of rock' has no staying power? I'm sure if you told people that he'd be irrelevant now a few decades ago, they'd look at you like you're crazy. Meanwhile, literally nobody gives a shit about Elvis unless they're trying to be different or for whatever reason had his music shoved down their throat.

There is contemporary music that will stand the test of time, like from Ulrich Schnauss and Felix Laband.

But have you even heard of either of those?