HELP??? In what fundamental way does one musical note differ from another?

Musical notes tend to differ from each other based on the material used to produce the strings as well as how long the string is.

Explanation:

Take for example, a grand piano. The longer and thicker the string, typically the more bass the sound is. The shorter and thinner the string, the more high-pitch it is. Each note differ from each other based on the sound produced by each string when it is played.