Answer:
pitch
Step-by-step explanation:
In music, the pitch is defined as the sound of the motes. The note lives on the staff provides the pitch. It is a perpetual property of a sound which allows an ordering of the frequency-related scale. Pitch is the quality of the sound which makes the music sounds 'higher' or 'lower' in terms of musical melodies.
There are 88 keys in a piano. And each key represents a different pitch or a different note.
In the context, Jamie is playing a piano and stared pressing the keys of the piano from the lower notes and then moving towards the higher notes before coming back down. And as Jamie is moving across the keys of the piano, the pitch of the piano is changing.