How can I repair my music library after iTunes Cloud has made a Hash of it?
First turn iTunes Match and iTunes Cloud off. If you have not added a lot of music you can't stand adding back manually, you can just go to ~/Music/iTunes and rename one of the Previous iTunes Library files to "iTunes Library.itl"and move it back up to the iTunes folder, leaving out the quotes. See the screenshot of my folder; the closer the file's date is to the date of the current file, the less adding back of music you will have to do. This does not add the music just the 'music  library stats'.