when filing your stuff do you file something like A Chorus Line as "A Chorus Line" or "Chorus Line, A" same for something like "An Ideal Husband" or "Ideal Husband, An"
iTunes automatically puts A Chorus Line under the "C" section, so I generally agree that it should remain there. But I read somewhere the show was originally called Chorus Line but the producers wanted it to be at the beginning of lists of shows so they added the "A." I don't know if the rules of alphabetization were different in the 70's though.
"Contentment, it seems, simply happens. It appears accompanied by no bravos and no tears."
In terms of official listings articles are counted as part of the title. Look at the weekly gross section here, or all the listings in the back of Playbill. A Gentleman's Guide is always first, all of the titles that start with The are near the bottom.
And that is indeed the standard story given as to why the show is titled A Chorus Line and not simply Chorus Line.
Of course you are free to file your own collection in whatever order makes the most sense to you.