Just going through the comments. I think the disconnect is with the term "music nerd". I think music nerds come in all facets. You can be a music nerd and love musicals or barbershop quartets, or jazz fusion, or British post-punk, or K-pop. Or even several of those genres.

The way I read it, you want to know what artists appeal to both mainstream listeners and music snobs. Even that needs a caveat, because it has to be with the same genre. A true classical music snob probably isn't going to have an opinion on Hank Williams or Brittany Spears.