I have read the following sentences:
So here’s what I’m thinking: This school year has been kind of a bust, but if I can get voted as a Class Favorite, I’ll go out on a high note.
What does “go out on a high note” mean? Is “on a high note” an idiom?
Yes, “Go out on a high note” or “End on a high note” is an idiom. It means to finish something well. There are two slightly different cases where I commonly hear it used.
It can mean to finish well, even though you’ve been doing poorly so far. This is how it’s used in your sentence. The school year has not been going well (“kind of a bust”), but they hope to finish well (“go out on a high note”) by being voted a Class Favorite.
It can mean that things have been going well, and they plan to finish while things are still going well. For example, when somebody says “Seinfeld (the TV show) went out on a high note”, the implication is that Seinfeld was doing well, and they decided to stop while it was still good, instead of letting the show run until it got bad and had to be cancelled.
Source : Link , Question Author : user48070 , Answer Author : Ken