Removing music from iPhone

Was trying to update my iPhone but was told not enough memory. Went to look and see that Music had a high amount of GB. Start looking through the list and see a bunch of albums that my son had purchased on our mac mini and I found a bunch of playlists that another son had created on the mac mini...... Normally when I connect my phone to my laptop and I click on the music tab in iTunes it used to show all of the albums and playlists and I could check the one to sync....now it just says iTunes match is on and all I can sync are voice memos..... So if I delete any of the albums or playlists am I truly deleting them from the phone or from iTunes completely?

thanks

Michael