One of the more inexplicable details in the movie version of The Phantom of the Opera consists of Christine confessing to her friend Meg that when she and Raoul were children, he nicknamed her Little Lotte. Lotte was a common diminutive nickname for Charlotte, not Christine. It seems that the dialogue was added simply to explain to the audience why they then sing a duet about Little Lotte.
So why does Andrew Lloyd Webber have a duet about Little Lotte in his musical, then? Simple. It's in the original story by Gaston Leroux.
Now we get to the crux of the issue. In the 1980's, when Phantom first debuted, no one knew who Little Lotte was. The offhand reference in the lyrics made no sense to most theatre-goers. But at the time when Leroux was writing his book, readers would have known exactly what he was referring to.
Little Lotte is a parlor game, similar to Twenty Questions, where one person knows the answer, and other people try to guess it. But in this case, the person lists three items, and the others must guess which of the three Little Lotte prefers. The secret is hinted at by the name of the game -- Little Lotte prefers items with double consonents in their names.
So now, we have the lyrics: Little Lotte thought am I fonder of dolls or of goblins or shoes?
The correct answer should be dolls because it has the double-L. Since they both know the answer, they don't bother answering, merely posing the next set.
Or of riddles or frocks? Or of chocolates?
Again, Lotte would prefer riddles, because of the double-D.
You can see why the game quickly fell out of favor. Once you know the secret, there's no challenge. And that's why modern theatre-goers needed an explanation for who Little Lotte was.