I'm old enough to criticize contemporary pop culture, so you can, if you want, think of this entry as just being an old man's rant.
When marsupial mammals reached the Australian continent, there was no higher mammal. Australia was plenty of empty environmental niches available for marsupial mammals, so they explosively evolved into a wide range of species, from Boongrays, which are an arboreal herbivore, to carnivorous Tasmanian Devils. This phenomenon is called Adaptive Radiation.
We can find similar phenomenon in human cultures. I call them "Cultural adaptive radiation". Rock 'n' Roll was one of the dance music styles in the black music world, which was imported into the white music world, and evolved into Rock. In the 1960s the Beatles created a wide range of rock music and showed the potential of rock music to evolve. The evolution of rock music in the 1970s was truly "cultural adaptive radiation". I love the rock music in 1970s, because I can feel the excitement of rock musicians who found new empty environmental niches to inhabit.
After adaptive radiation, environmental niches were saturated, and the explosive evolution of marsupial mammals stopped in the Australian continent. In the same way, the evolution of rock music stopped in 1980s. After the 1970s, grunge was the only new style of rock music. Hip hop, which was created in the 1980s, is the last "new" style of pop music. The pop music world is saturated now.
As I wrote in an entry, "Now it's bad times for music producers, but it's good times for listeners. We, listeners, can get everything far more easily through the internet." Now, I mainly listen to 1970s pop music, which got through the internet, because I feel that contemporary pop music isn't excited.
I think that there is no new sound but just combinations of old pop music in the contemporary pop music. When I listened to contemporary pop music I often feel that young musicians study old pop music very deeply. I guess that they can't find new empty environment niches and make an evolution.
I wrote in another entry, "I think that rock music isn't contemporary music now either. Hip hop killed Rock music in the 90s, and Nirvana was the last band that created new rock music." Now, rock music is an endangered species like Tasmanian Devils.