iTunes does not delete music simply because (or when) you copy it to your phone, so something else must be going on. If it's not Apple Music, are you using iTunes Match?
When you rip a CD into your iTunes Library, it simply becomes part of that library. Copying it to your phone does not delete it from your library as that library is your backup of the music on your phone. Your library basically consists of two lots of music:
- music purchased from the iTunes Store
- everything else, that is rips from CD and purchases from other online stores
The reason they are different is that your device (the phone) needs to be signed into your iTunes Store account in order for the music purchased from the iTunes Store to be playable. This is not Apple Music or iTunes Match. It is simply being signed into your store account so that the store can confirm that you are authorised to have the songs. Effectively, purchases from the iTunes Store are (or can be) downloaded directly from the store, whereas music from other sources (CDs etc.) has to be copied from your library, not from the store. To emphasise the point, music from CDs, or other online stores such as Amazon and Bandcamp etc., does not need to be authorised, it is simply copied from your library to the phone and the original remains in the library as your first line backup, should the phone fail, be lost, stolen or require a Restore.
JoshuaCM wrote:
Itunes seems to delete music that is also available on itunes, or apple music.
Then that must be due to iTunes Match, or Apple Music etc.
I would like to not have to add the CD back from my library every time that my phone syncs and is backed up if it is possible.
You should not have to. I don't and I've used iTunes for many, many years.