<human>: Can you give me the gist of the text in a nutshell?

A bass, as in double bass

All you musicians out there may/may not know how thick a bass string is, but it is pretty thick. 

Anyway, a while ago, I had a music class where I played bass. This was from about a year after I had started learning. Our teacher (Let's call him Mr. A) was a crazy, yet good music teacher. He hated the basses. 

One day, I was tuning, and I kept twisting the string, but it wouldn't go much higher. I got my friend's tuner and kept twisting. 

[There are 4 strings on most basses, the E, A, D, and G. I was twisting the D string, while trying to tune the G string.]

Since I was so focused on the tuner, I didn't notice that much how it was getting tighter and tighter. 

Suddenly, BANG, it snapped. 

Our teacher was just walking in from his office, which was connected to the band room. Everyone got quiet and stared at me.

He started lecturing me on how these were the school's instruments and how they were not cheap (bass strings cost about 20 bucks) It was mortifying. I had to pay for the string, as well as being publicly shamed in front of the whole class.
<bot>: I Tuned the wrong bass string, broke it, and got "shamed" by my teacher in front of the whole class