It's not as if at any given time there's only 1 concept that's being used by all K-pop groups.
To the contrary, there's always a large variety of concepts, themes and styles used by K-pop groups in any era.
But there's always some concepts that are more popular and more frequently used by groups, and which those most used, dominant concepts are varies over the years.
There was the cute/bright concept that got very popular due to SNSD and other 2nd gen groups and that saw a return to popularity in 3rd gen era with TWICE's rise.
Then there was the sexy concept that was very popular when groups like Sistar and Girl's day had their peaks - only to fade away after them.
And let's not forget the girl crush style that with the growing international popularity of K-pop has become a dominant theme the past few years.
Which brings me to the Retro concept.
I'm sort of catching up with K-pop songs of last year, and I noticed that last year saw a noticeable increase of retro concepts, themes and styles being used among the top K-pop groups.
Not that before there were no songs with a retro concept at all.
But lately it seems a lot more songs with a retro concept have been released by the top K-pop groups.
It's also very diverse: there's songs with a disco '70s concept, songs with an '80s vibe as well as songs with that '90s/early '00s hiphop and R&B style. By both boy groups as girl groups.
I'm not complaining btw: it's interesting to see how all those old (and sometimes ancient) styles are being dug up and re-used, often with a contemporary twist and music styles to them.
I'm just wondering, I haven't exactly kept up-to-date with K-pop: so, is it just a fluke, or is retro style really the rising trend now in K-pop?