Thanks guys, now i see its a style guideline I can of course program around it. Unfortunately both mysql and PHP don't seem to treat this character as the same without special processing(I'm matching the iTunes RSS feed with the MusicBrainz Release-Group name). Again not a problem, I really was interested in why it was sometimes different. Even on the same Release-Group!
For anyone who is interested here is how I solved it in both:
UPDATE album SET release-group = REPLACE(release-group,"’","'");
$output = iconv('UTF-8', 'ASCII//TRANSLIT', $input);