The 4th gen is Pokémon's BTW. I explained my whole Gaga/Pokémon theory already a lot of pages ago, but let me just do it again
The 1st and 2nd gen was on the same console (GameBoy). This relates to Gaga's first two albums, The Fame and the Fame Monster, which are two seperate albums, but still links to each other because of the EP/Re-release situation.
Then we have the 3rd generation, which was a huge succes, but still a drop from the first two gens, which is exactly the same as Gaga's BTW.
Then we have the 4th and 5th gen, which were released on the same console, that means that ARTPOP will be released in 2 parts/rerelease etc.
ŕ la the 1st and 2nd gen
I see you Gaga