Can I just buy rock band 3 and export the songs? (ps4)

So I have rock band 4 for ps4 and I wanted to know if I can buy rock band 3 game and export the songs to my account, I've searched around, my question is how the game will recognize that I have the game rock band 3 since I don't have ps3 physical device.

Also if I will buy a used rock band 3 game will I can still use it?