I've been thinking about this for a long time. We've been limiting ourselves on expectations and preferences within certain styles of music, then ridicule anything that tries to be different.
Most of the time bands are made up by pure coincidence of networking. The sound is limited by talent and/or choice of instrumentation not creativity. People get used to that certain sound, and believe that's the only way to do it. It becomes a style. Then it becomes a requirement. It's only until someone willing to be creative, and popular, do people realize they can do something different and still be within a recognized genre.
Even within our own discipline of bass guitar, we are prejudiced by gear and technique.
Some folks cite The Doors. Sure, they initially didn't have a bassist, they rocked, they became popular. Eventually, they decided they needed to conform to the standards of having a true bass guitarist.
The Presidents of the United States, they rocked. They didn't have a true bass-guitar, just modified guitars while one player was delegated to "bass lines."
The White Stripes would play without a bass-guitarist. Most likely bass playing in studio recordings (beats me, I don't listen to them), but I've seen live videos with just the two playing and they do that rock and the roll.
It makes me wonder how should I define "rock." The musical end-result? Or the specific instrumentation used to make it? Certainly if I want to mimic a previously done sound, it helps to mimic the instrumentation. I do realize "rock" incorporates a lot of styles, genres, sub-genres... whatever. My current definition of what rocks can be entirely different from another person's.
Technologically, we have things that can mimic a bass guitar. Not perfectly, but just enough so an audience will hear what most modern music uses: low rhythmic harmonies. I just refuse to believe a genre can only be acceptable by incorporating an amplified plucked (or picked) thick metal string.
Fortunately, most people don't think like I do, so I retain my bassist job.
