What is route that does not get too secluded?How long of a route are you looking for?
All the typical coast to coast routes have a lot of fairly remote country. Still even on those you meet some really nice folks in the tiny towns they pass through and you could choose to go into bigger towns and cities more often if you want. Both the Atlantic and Pacific coast routes will be more populated, but will still have more remote feeling sections than you might think.
The Crooked Road in rural Virginia has a music theme. It would involve some difficult climbing though. It is 333 miles long. The Blues Highway runs from Chicago to New Orleans. I have heard varying opinions on how suitable either might be for a bike tour, but at a glance both looked interesting to me. You would need to do some research to see that they were suitable routes.
Either of those have a music theme that would likely make it easier to meet other musicians, neither is established as a bike touring route as far as I know.