I just bought my new MacBook Air and I set it up easily. However, while I was trying to bring in music from one of my accounts, it only showed things I bought with that account. That's obvious. My iPhone 6 on the other hand, has bought music with both of my accounts and shows them both. I want my MacBook to have music from both as well. How can I do this?
MacBook Air
Apple's 6 pages of exhaustively meticulous step-by-step instructions: How to move your iTunes library to a new computer - https://support.apple.com/HT204318 Use this if you suspect any of your media are not in the standard location (iTunes Media folder).
My one-sentence summary if you always use iTunes' default preferences settings: Copy the entire iTunes folder (and in doing so all its sub-folders and files) intact to the other drive, hold down the option/alt key (shift on Windows) while starting iTunes, and when requested to select a library select the iTunes Library.itl file in the copied folder (Open a different iTunes Library file or create a new one - https://support.apple.com/HT201596).
When this is to a new drive/computer put the copied iTunes folder in the default location of Macintosh HD > Users > *User Name* > Music (or Home > Music) then you don't even need to start with the option key held down, iTunes will automatically look for it there. (Make sure there isn't anything already in the iTunes folder there that you want to keep since you will be replacing it with the one you are moving.) Remember to authorize the computer in iTunes to your Apple ID if you use this to sync to Apple mobile devices or play DRM protected media (e.g., movies).
Copy everything from your old computer or your backup copy of your old computer.
Make sure that you authorize the new computer for both accounts
Transferring Music From Different Accounts
