This sort of came up in the "Dirty Old Town" thread recently, though not formalised as "universalisibility" (what a mouthful - I can't say I like the word!). Although written about Salford, the song was written in such a way that (perhaps apart form the Gasworks croft) it could apply to just about any industrial town - I think that was more or less the consensus. For that reason, many of us could relate to it, even though we may not have been to Salford itself.

But a song like Route 66 mentions many places that, if you haven't been to them, perhaps mean little - they may be just names. I've never driven along the famous highway, but I can still relate to the song to some extent, as I picture (probably wrongly, not having been to most of them) the towns mentioned. I guess I've seen enough movies to be able to visualise driving along the road (and I've been to the USA and driven along what I imagine are similar roads - again, probably wrongly, but as long as I can picture it that way, I can relate to it).

As for songs about relationships, love, etc. I guess these are pretty much universal. Even if they're about a sailor or a soldier, you can still relate to the characters even if you've never served in the navy or army. Things may have changed since the 18th century or whenever, but a lot of the sentiments expressed in these songs still resonate today (maybe that's why we keep singing them).

I suppose this is all a bit rambling and inconclusive. I'm not really sure where you draw the line between "universalisibility" and "non-universalisibility". I'll shut up now and see what others say.