This song is about the reformation with the catholic church. 7th graders learn about when learning bout europe in the middle ages. This is in like the pope or the churches point of view I'm not sure. When he says "key" he means the key to heaven. "never an honest word. but that was when i ruled the world" he is saying the church scammed the people cause they couldn't read. For example the indulgences they use to sell. When he says "wicked and wild wind" hes referring to martin luther. "saint peter wont call my name" it is said that saint peter is at the gate of heaven or somthing and he wont be going there cause hes been bad. "just a puppet on a lonely string. oh who would ever want to be king" basically the pope had total control over the king. Cuz like he could excommunicate them and that was bad back the cuz there werent many churches.