Yes, it's rather an old one from this era's point of view. [She can kind of see Nike's point once she explains the thing about idols, though, because that definitely sounds like a disparity in meaning.] While it's true I could use it regardless because of being called a goddess, in this era an "idol" isn't just used in the religious sense. For example, if you consider someone your "idol", it's someone you want to live up to and be like. That's more the sense the musical idol uses the word in.

[Hopefully that's a sufficient explanation on the meaning change.]

If you go looking online, it'll certainly be easy to find popular music that they'd have on the machines, so you can decide what you'd like to sing before you come. And yes, it can be tiring, but it's an uplifting experience nonetheless.