That’s the opener of the first song, and of course most of the episodes. It’s all very confusing actually, made worse by the fact that most people think The Prisoner is basically a continuation of Secret Agent Man which itself had a very popular theme song with lyrics. Luckily I’m a fan of both Iron Maiden and The Prisoner from completely separate paths.
Yes, it is confusing, especially if you can’t remember it. Almost every site I saw about the Prisoner evolved into something about Secret Agent Man!!
So, that WAS the opener of the first song. Thanks for telling me that.