Can anyone tell me whats it mean when theres a version 2, 3, 4 etc of a song?
He means they are DIFFERENT, as in the actual notes. This is because we usually don't know which one for sure is right, some sound more right than others, different tunings, etc.

So they're different.
Different people's interpretations.
Populus vult decipi. Decipiatur.

Quote by Mistress_Ibanez
It's can be a contraction and genitive case.

Quote by Mistress_Ibanez
If you cut down on these costs students won't learn so well, effecting the "quality"...