The Boy Who Said Wow by Todd Boss and illustrated by Rashin Kheiriyeh is currently available, but I read it via an online reader copy. Based on a true event (a 2019 Mozart concert performed in Boston, attended by a nine-year-old nonverbal child named Ronan) this is a delightful story about the power of music and words. When a mostly nonverbal child experiences a concert for the first time with his grandfather, in the silence of the aftermath he expresses what he is feeling with the one word everyone was thinking: Wow. Timing is everything and this young boy has perfect timing in this sweet book. 
The action is the fact there is none, as Ronan is not a very active child. His parents suggest grand adventures, but he just sits still, quietly being Ronan. When his loud, boisterous, well-meaning grandfather takes him to a concert, things seem shaky at first, but turn into the adventure of a lifetime. The music comes alive on the pages with booms, crashes, flying feelings and colors galore. The details are minimal, but keep the pages full and the story moving. 
The images have an old school, classical feeling to them, as well as modern elements. The parents of Ronan look as though they were the parents of The Beaver and Wally. Even Ronan has a proper outfit. The colors reinforce this tone and makes the themes of being yourself; being different and music come to life in a fresh manner, and yet allows a bit of cozy nostalgia. 