I didn't understand key signatures in front.

我不明白前面的音调符号。

And, " Oh, yeah, key signatures. That's a great concept." It's 500 years old, right?

“哦，是的，音调符号。这是个伟大的概念。”它有五百年的历史，对吧？

This is a key signature for differentiating a nuclear explosion from any other kind of man-made or natural phenomenon.

这是区分核爆炸与其他任何一种人为或自然现象的关键特征。

So, that's the key signature, as you know for G major.

所以，这就是 G 大调的调号。

Key signature, one sharp, G major or E minor.

调号，一个升号，G 大调或 E 小调。

Okay, so that's called a key signature, just like this is called a time signature.

好的，这叫做调号，就像这叫做拍号一样。

Or it could be what's called the relative minor; would be E minor with the same key signature.

或者它可能是所谓的相对未成年人；将是具有相同调号的 E 小调。

I didn't know there was a key signature of a flat on the third line that would take care of all that.

我不知道在第三行有一个降调的音调符号，它可以注明显示这样的问题。

This one, I've given it a key signature for F major with one flat.

这首，我给了它一个降 F 大调的调号。

And there's also the key signature, there, for the key.

还有密钥的密钥签名。