Timeless music is timeless music, there’s no formula for that, it simply connects with the population in general to a point that it becomes a staple or you can even relate memories to that specific song.
In my own experience:
Started to hear hip hop in 2002 with the 8 mile soundtrack, then got to know 50 cent. Though the years that followed, became a regular 50 cent listener, but heard all the hot songs from other artists in 03, like dmx and Sean Paul, as an example. 04 usher, groundbreaking “yeah” and crunk music a lot, 05 had a lot of good ones too, like jeezy.
After 05, I think that’s when music in general became tricky for me, personally. Because I remember cats like young joc, hurricane Chris, Soulja boy, Jibbs, Chamillionaire, rich boy, a after a while, the artists themselves, became disposable in my vision. In other hand, the ones that was “cemented” I would always keep them on my iPod, but this newer ones my interest in them would diminish after a while, and Ended back on 50, jeezy, Wayne, Kanye and such.
The end of 00’s had the proeminence of drake blowing up, but I can also put in perspective cats like Charles Hamilton, b.o.b, and Asher Roth, as cats that came and went, but b.o.b left a bigger impact than the other two.
In the 10’s things are faster than ever. I can’t even think of anyone blowing up after 2012 that’ll last longer than 2 years.
Bobby shmurda had some potencial in it, but blew his chance.
Joey badass is the one that is staying more relevant, but I can’t remember him as back as 2012. Asap crew also. Chief keef also. Future also. Odd future also
These are the ones that are still relevant.
Aside from few names like the ones I’ve mentioned , my impression is that after 2012 ain’t nothing new in hip hop powerful enough to stay relevant longer than 1/2 singles or years. Designer came and went, young m.a came and went, and now we have a new wave with a boogie, lil pump, lil uzi, lil yatchy, xxx tentacion, and all we gotta do, is watch how it plays out.
So the quality of the material, and how the artist translates into de population or alteaste connect to society in general have a huge relevance on how long their shelf life will be. At the end of the day a lot of these cats get forgotten along the way, and I end up on 50 cent, jeezy, Kanye, Wayne, jay z...