deleted songs on iphone still showing up as on iphone when connected to itunes/ computer, and can't re-download to iphone

Ok, so the issue I was encountering was that I had manually deleted a song/album from itunes on the iphone, and then when I synced the iphone to the computer to re-download the song/album back to the iphone it was showing up that the song was already on the iphone, so it would not re-load it back to the device (since it already thought it was there). The work-around that I found (other than re-doing the entire device or re-copying every song from scratch was to plug in the device to the computer. go to the Songs in the library, and un-check the songs/album that are showing up as already on the iphone. Then go into the iphone by top left (square icon button showing the iphone in the square) Then, go to Music, under "On My Device." Click on settings next to autofill, and choose replace all items when autofilling. You will need to then choose the Autofill option (assuming you are OK with ALL the other music that is in your library WITH A CHECK MARK NEXT TO IT getting loaded onto your iphone/ ipad- if not first uncheck all ather content you don't want the autofill feature to load to your device). Then go back to the library, and recheck the boxes next to every song that you want back onto the device. Go back to the iphone icon, back to the Music, under "On MY Device," click autofilll again, and it will finally realize that the album isn't already loaded onto your device, and will re-download a manually deleted song/album back to your device. Hope this helps with what should otherwise be a simple task of itunes realizing/ recognizing it was deleted from the iphone.