Pop music seems to be so popular, especially on the radio nowadays.
I enjoy pop music. It actually started back in the 1950s in the US and United Kingdom.
That long ago? Cool! I quite like it too, honestly.
Yes, it usually includes songs that are short or medium lengths, written in your usual verse style. 
That seems pretty consistent with what has been being made a lot recently.
Pop music is pretty eclectic too. It takes elements from urban, dance, latin, rock, and country music. 
I've noticed that recently, it has a lot of different styles melded into it.
Yes, back before the 60s, rock and pop were considered the same, but in the 60s they started differentiating it.