Origin of "karaoke"

My teacher taught me something interesting at my lesson this week. I've been noticing that 「カラオケ」(karaoke) is always in katakana. I asked her why this is. "It's a Japanese word, isn't it?" It sure sounds like one...

It turns out it's a hybrid!

The kanji「空」can be read「そら」, which means "sky," and is probably one of the readings we're more familiar with. But it can also be read「から」, which means empty.

Next: 「オケ」. It turns out 「オケ」is actually the first part of 「オーケストラ」. They decided 「カラオーケ」just didn't sounds nice, so they shortened it, which gave us what we now know as 「カラオケ」.

So what does it mean? Yes, you're right: empty orchestra.