My entire music library––1,000-plus albums––lives on a hard drive and is ripped to Apple Lossless format; some of the files are 24-bit and 48/96/192kHz. For years, I've gone to considerable lengths to ensure that I'm using the highest-quality files that I can. After getting started with Apple Music, iTunes prompts me: Use iCloud Music Library? Since you have music on this computer, your playlists and songs will be combined with your iCloud Music Library. You can change this in General Preferences. What happens if I select yes? Will iTunes use Apple Music's lo-res streams for all of my music file instead of my local high-quality files? FYI - I've been an iTunes Match user for years and have my local library matched with lo-res ALC files to my iPhone and iPad. It's worked extremely well. Before I do anything, I want to ensure that iTunes (1) will continue to use my local files; (2) doesn't screw anything up.