What is a semitone in western music?

A semitone is indeed known as the smallest interval used in Western music. It represents the distance between two adjacent keys on a piano keyboard, for example, moving from C to C# or from E to F. This interval is significant because it forms the basic building block for larger intervals and scales in Western music structures, such as major and minor scales.

Understanding the concept of a semitone is crucial for musicians because it underpins the construction of chords and melodies, and influences how we perceive musical movement and tension. In a system where larger intervals, like whole tones, are made up of two semitones, recognizing the semitone as the smallest interval helps clarify the hierarchical nature of musical intervals.