To solve a simple heist

Question

It happened by chance really. I was walking out from the bank when a man ran into me while rushing out. During our collision a piece of paper fell from his pocket.

I quickly picked it up and tried to call out to him, but he had vanished. I then looked at the note and was instantly intrigued.

It said:

Be where?

I looked further down the note and saw something strange. It had a piece of music taped to it:

Below in a scribble it said:

I'm not sure what all this meant. So I continued to look at the note.

I turned the paper over and my heart sank. It was a blueprint of the very building I was in!

Below the blueprint was an object and strange text circled.

Were these instructions on when to rob this bank?!

I had to solve the puzzle so I could go to the police. But how to solve it?

So answer me this:

What time was the heist?

What were they going to steal?

Hint 0:

The : in the music staff normally means repeat, it does not.

Answer 1

They were stealing

a diamond at 23:25.

The notes read

AABBAABA AABBAABB : AABBAABA AABBABAB

Alpha Centauri A & B are a binary star system, hinting that we need to use binary to translate this.

So, convert to binary (A=0, B=1):
00110010 00110011 : 00110010 00110101

Which in ASCII reads 23:25

Modified Newtonian Dynamics is

abbreviated MOND, and prefixed with the "die" we get diamond.