Impression is to use music to construct a picture, and you can write this artistic conception. Good music interprets a moving story.
If it is purely an exam, you can describe this music as a story, but exams are often positive, so you must depict brilliance, sunshine, struggle, upwardness, and longing for the future. The ups and downs of the story should fluctuate with the speed of the music.
I think the key point is to grasp the rhythm and key points of the music, then use a few keywords to summarize them, and finally write around these few words. I hope you are very satisfied with the exam.
It’s so tiring to describe
The Fox - Ylvis
Dog goes woof
Cat goes meow
Bird goes