Artists that use the same song structure...

Czarivey, trust me, it takes genuine talent to play bluegrass well. I don't care for most of the modern examples of it but I respect the musicianship.
You can also sing Folsom Prison over the changes to Pinball Wizard, and vice versa, but that doesn't diminish the value of either song IMO.
Not a fan of Phillip Glass, but at least he's repeating himself intentionally to achieve a certain effect.
Anyway on the bluegrass the new vocal people mostly don't ring my bell (I like Tim O'Brien) but the instrumentalists such as Sam Bush, Tony Rice and Jerry Douglass are phenomenal musicians. It takes real skill to do what they do. Try it some time.

Completely agree with Tostados re bluegrass. The playing by some of those guys (and gals) can be fantastic sometimes, in an earthier way than other genres. Some of those bands swing their asses off. As far as the song structures go, as usual, until one delves into the music one doesn't really get it. I had that experience recently with a friend who is a classical clarinetist and an accomplished Irish traditional music player (on the clarinet!l!). Not until I gave the music more than a causal listen did I understand just how much "there" is there.

Btw, anyone who is quick to give avant-garde short shrift, give this a listen:

https://m.youtube.com/watch?v=cklbhkm1HrE

I once heard a 3 sheets to the wind Roy Clark, who could play anything written for guitar , answer why such a skilled musician as he played and excelled in country.
His reply" Because it takes a real musician to play out-of-tune ALL the time " .

Czarivey,

Doc Watson was a wonderful player, but Bluegrass is full of spectacular guitarists. Check out Jerry Douglass (primary guitarist for Alison Krauss and Union Station) or Tony Rice or Bryan Sutton, among many, many others. I understand that you may find the general tonality of the genre off-putting, but there's wonderful playing talent shot throughout the bluegrass catalog. You may not find it worth the effort to acclimate to the form, but - if you do - you may be pleasantly surprised by what awaits you.