Ontimpr3. What is a mistake?

According to dictionary.com the word "mistake" can be used as a noun or a verb.

As a noun it is defined as:

1. An error in action, calculation, opinion, or judgment caused by poor reasoning, carelessness, insufficient knowledge, etc.

2. A misunderstanding or misconception.

As a verb (with object) it can mean: to regard or identify wrongly as something or someone else, as in "I mistook him for the mayor." Or to understand, interpret, or evaluate wrongly; misunderstand; misinterpret.

The word can also be a verb (without an object) as in: mistook, mistaken, mistaking, meaning: to be in error.

Notice that all of these actions mentioned can be done by a performing jazz musician. Let's go through the list with examples:

An error in action: a musician could stumble and as a consequence misplay her instrument.

An error in calculation: a musician could miscalculate the number of beats or measures in a song.

An error in opinion: a musician might have an opinion that this beat is the one when it is not the correct rhythmic timing.

An error in judgment caused by insufficient knowledge: he thought this was how the bridge was played, but it isn't.

A misconception: she conceived the song in the wrong key with what they were playing.

To evaluate wrongly: the musician thought it valuable to play out of tune.

Of course there are numerous ways a musician can be in error, as listed at List of Types of Musical Mistakes.