How do I deal with 2 Apple IDs?

Question

Over the years I've used two Apple IDs to make purchases from the ITunes store, and now that I've started iTunes Match, it's a problem.  I initiated Match on my MBP and t worked, but when I turned on Match on my iPhone and iPad, it didn't access any of the songs stored in iCloud because the iOS devices are signed on to a different account from the music purchases.  Each iOS device said I could sign out and sign in on the other ID, but I wouldn't be able t change that for 90 days.
Is there any drawback to changing the ID? Is there as any way I can transfer the songs from one account to another?  Can I combine the two accounts?

Answer 1

This method does work from first hand experience.  The steps are as follows:
1.  Start from a secure backup of your source libraries;
2.  Create a new library and import from your first chosen source;
3.  Once loaded 'select and play a song' you will be invited to authorise if the computer does not already have the corresponding Apple Id registered with Apple;
4.  Import from your second source;
5.  Once loaded 'select a song that you know is only authorised as part of your new import' you will be invited to authorise once again (as in step 3).
The result is a library that is licensed to play songs from both Apple Ids.  Use this new library as the source for the iTunes Match service.  Worth taking separate back-ups of the library both before and after the initial matching to allow you to restore any files as needed in the future.
Once iTunes Match is complete and the backups are secure.  You can at your discretion associate other computers and IOS devices with the iTunes Match service with the ability to download those tracks that have 'matched' or have been 'uploaded' - worth noting uploads do take a long time to complete, worth running overnight / for several days as needed depending upon the size of your library.
Good luck!