Recognition of Keys

Naming Scales

Unfortunately, the name of a scale will not always be given, therefore it is crucial to memorize the key signatures (and accidentals for the harmonic and melodic minor scales) of all mentioned scales and which key they belong to.
Doing this will also enable you to write these scales, which is a skill that is important to have.

The Key of a Passage

Knowing the the key signature and accidentals of the keys we talked about is a skill set that can be used to identify the key that a passage (an excerpt of a piece) is written in.
Spotting recurring accidentals is crucial to telling whether a passage is written in a major key or in its relative minor.