Esperanto was not a new language when Incubus was released...

I see comments here about how the film makers thought that Esperanto would soon become the world's international auxiliary language (which turned out to be a failure), which is the reason they made it in it. This is wrong. Esperanto was published in 1879; that's 86 years before Incubus. If Esperanto is a failed project (though, it's not a project; that's what separates it from the other attempts to IALs) today, then it was a failed project back then too, as more people speak it today than in 1965 (it's most popular in the Far East). Trying ethnic languages, Esperanto is far easier and I'd really recommend it if you want the advantages of knowing another language but don't want to invest into learning another language; even Spanish is about four times harder (I'm studying Spanish right now and it's just incredible how many things are both harder and less flexible in Spanish).