I wish I’d read this first. So far, I think I’m okay because I didn’t use the iCloud music feature. But before you upgrade, consider the risks. From Mashable:
A day after the launch of Apple Music, users are reporting an iTunes bug that is wrecking music libraries by scrambling artists, albums and tracks.
Apple‘s tagline, “All your music in one place,” implied there was finally a solution to having your music spread out across different services and devices. But one of the key features aimed at making that a reality, iCloud Music Library, may have been the culprit behind the scrambling of iTunes libraries on Macs.
After I updated to the new iTunes 12.2, I was asked to enable iCloud Music Library, which is supposed to sync your tracks across your devices. Once it was enabled, iTunes randomized the majority of my roughly 25GB library. Tracks moved across albums, album art didn’t match music and artists were listed up to seven or eight times.
Read on. Seriously.