In my opinion most music released since 1990 sounds modern enough. It doesn't sound retro. Especially after 1995, I feel like music has somehow reached peak "modernity". Now it just changes, different styles, etc... but doesn't progress in sense of sounding more and more modern each year.

There's a lot of stuff in the 1990s that sound as modern as anything today, some stuff even sounds futuristic.

It might only sound slightly retro due to nostalgia, if you remember listening to it 20 or 30 years ago, but not due to intrinsic properties of the music itself. If you just consider music it sounds very modern.

I have a classification of "retro", it goes something like this:

pre 1970 - definitely retro

1970 - 1990 - some stuff is retro some not, depends... generally some retro vibes are present

after 1990 - not retro

Agree, disagree, discuss?