a Finder search for recently modified files shows only the track itself; neither ~/Music/iTunes/iTunes Library nor ~/Music/iTunes/iTunes Music Library.xml appear in the search results
Finder (actually, Spotlight) considers these "System" files, and won't show them unless you explicitly include {System files}{are included} as a search parameter.
Tip: "System files" is considered an obscure search term, so it's not included by default in the criterion popup menu (the one that initially says "Kind"). You need to select "Other...", which brings up a sheet with a long but thankfully alphabetized list of search terms.
Tip: That list is so long it's hard to scroll through. Fortunately, there's a search field right there on the sheet, so you can search for "sys" to jump straight to it. Searching for search terms! Who'd'a thunk it? I love it!
Tip: When you find it, there's a checkbox associated with it. Putting a check mark in the checkbox keeps it in the menu, so you never have to search for it again.
