Learn Hardcore Russian: Не успела я открыть ноты, как учительница попросила начать сначала. - Hardly had I opened the sheet music when the teacher asked me to start from the beginning.

Breakdown of Не успела я открыть ноты, как учительница попросила начать сначала.

What does the pattern Не успела ..., как ... mean here?

This is a very common Russian narrative pattern.

Не успела я открыть ноты, как ... means something like:

So the structure не успел(а) X, как Y highlights that the second action happened almost immediately.

It is not just a simple logical negation. It often adds a feeling of suddenness or immediacy.

Why is it успела and not успел?

Because Russian past tense agrees with the gender of the subject in the singular.

Here the subject is я, and the speaker is female, so you get:

So:

Why is я placed after успела instead of before it?