pitch
In German, the word "Tonhöhe" is used to describe the highness or lowness of a musical note or sound. It is a compound noun, consisting of "Ton" (tone) and "Höhe" (height). For example, you might say "Der Ton hat eine hohe Tonhöhe" (The tone has a high pitch).
The pitch of the melody is very high.
This sentence is describing the pitch of a particular melody as being high. That means the melody has notes that are closer to the right side of a piano keyboard, for example.
He cannot control his pitch when he is nervous.
This refers to a person having difficulty controlling the pitch of their voice when they are nervous. Pitch in the context of sound is a perceptual property that allows the ordering of sounds on a frequency-related scale.
The pitch in his voice has changed.
This sentence is noting a change in the pitch of a person's voice. This can be due to a variety of factors including age, emotions, or health.