After this, I believe I'm out of points to present—so one last try:
If the artist intended to use it, then our first style principal is follow artist intent.
We correct typos, spelling errors, etc., yes. Correcting
’ (though really, its often right on the album—and the style guideline to use proper Unicode punctuation instead of the ASCII versions is at least as much about not being lazy when entering the data—it's much easier for most people to type
But if an artist intentionally used ASCII quotes, or even TeX-style ``quotes'', then we'd preserve that (e.g., maybe its an album of songs about mathematics, and the liner notes tell us that TeX-style quotes were used on purpose).
But a lot of this seems moot point: You're not arguing we should correct it according to (a) standard written English. You're arguing we should make/keep it wrong in a different way: Neither tilde nor any tilde-like character has any use in English that'd make sense in that track listing. In English, a title and subtitle are separated by a colon; multiple works (at least here) by a slash; and different tempo markings used as names by an en- or em-dash.
I think there is a fairly strong argument that it is:
- There is a tilde-like mark on the page. It appears to be part of the track title (and not some stray decorative mark, etc.). I think we all agree on both of these.
- The composer (& artist we credit with the work), is Japanese and presumably speaks Japanese. In addition, Wikipedia lists one of his other occupations as typesetting... so it's pretty safe to presume he's familiar with Japanese punctuation.
- The release was for sale in Japan. As evidence, I offer that (a) the release has plentiful Japanese text; (b) the promotional material on the obi (both front and the ad for an upcoming release on the back) is in Japanese; (c) the price is given in yen; (d) to buy it I had to import it from Japan. [d is obviously the weakest of these.]
- People in Japan (where it was sold, see above) can, I think, be presumed to familiar with Japanese punctuation.
- There does not exist any English punctuation that makes sense in that context. Tilde (of any sort) is barely used in English at all, mainly being used to say "approximately five" as "~5". It is also, according to Wikipedia, used in a special way in dictionaries (which this is plainly not).
- The usage of wave dash matches with what we see on the album.
That, to me, is not pure speculation. It's a pretty convincing case. Especially when there is no evidence to the contrary.
However, just to be sure, I went and did some more research. I found the album on the composer’s web site. He uses as wave dash on this release’s discography page. (Given his lack of spacing around parentheses, I don't think he really understands English punctuation, though...)
Sure, maybe he has an underpaid web designer who randomly changes the composer’s tildes to wave dashes, maybe he enjoys using English punctuations in nonsensical ways to confuse his audience, etc. But then, maybe the release isn't actually "Castle in the Sky"; it could be "Ⅽаѕtⅼе іη tҺе ՏkУ". How do you know that C isn't really Ⅽ (the Roman numeral for 100)? Makes as much sense there as tilde does in the titles.