What does "bring you in line" mean in the context?
Does it mean to correct or amend someone's mistake?

Well, that’s because we see songs as something that has to be performed accurately each time. If you change a word, the others will usually bring you in line.

Question

What does "bring you in line" mean in the context?
Does it mean to correct or amend someone's mistake?

Well, that’s because we see songs as something that has to be performed accurately each time. If you change a word, the others will usually bring you in line.

Answer

It's the same as "put you in line".  Usually, these expressions have a harsher implication than just saying "to correct someone".

Answer

PHRASE

If you keep someone in line or bring them into line, you make them obey you, or you make them behave in the way you want them to.

All this was just designed to frighten me and keep me in line.

...if the Teacher fails to bring rebellious students into line she will have problems with the Education board.

Answer

Yes that is exactly what it means. They are saying that they will be putting you back on the right path, or at least ensuring you don't go too far off it.