[I_Am_Nous]

Depends on what you are listening to and the band's decisions. Not quite 80s, but Metallica released an album with nearly all the bass guitar ducked. On the other hand, something like Duran Duran or The Police wrote their music not to thump, but to have the bass guitar actually carry part of the melody. Modern music uses bass quite differently than older music, and what many people think of when they think about "bass" is usually the really rattly sub-bass that only subwoofers can really produce.

80s music was intended to be played on a boombox radio with no sub-woofers and still represent all the sounds the band recorded. In the end, it's just one of the ways music has changed over the years.

[JohnFen]

I've become very interested by the difference between modern popular music and that of decades gone by. The three main things that I've noticed is that older music tends to be more melodic generally, makes greater use of dynamic range, and has more complex rhythms.

One of the standouts to me is what you mentioned -- in older music, the bass often does heavy melodic lifting and in newer music, it tends to be mostly just carrying a beat.

Not saying one is "better" than the other -- that's a matter of taste. It's just interesting to note the change.

It's also interesting that if you ignore music after the '80s and just compare '80s to the decades before that, you could accurately say something very similar.

It also depends a lot on what musical genre we're talking about. Not all '80s music was new wave and the like.

[I_Am_Nous]

Another fun thing to consider is older orchestral music as the "gold standard" for what music as theory intended. If an orchestra had the same amount of bass modern music does, it would have to be very heavily overpopulated by low brass instruments to the detriment of the rest of the instrumental ranges. Instead, each instrument is a "sound" which can be used to craft a greater musical phrase. A good example of this is a pipe organ, which has stops to add/remove particular sounds, ranges, and timbres depending on what kind of music you are playing.

Compared to modern music where the instrument isn't limited by the sounds it can physically make (due to digital production) as well as the things they make each instrument do, as you said much of modern music is carried by a beat rather than a melody, so a vocalist might be the only discernible melody. Back to a pipe organ, it would be really difficult to play a modern song on the pipe organ as a result because the structure is so different that it's hard to really compare. However, the pipe organ was a marvel in that it allowed a player to basically BE the entire orchestra if needed.