Which of the following best defines an interval?

A:the number of notes within a chromatic scale
B:
the range of notes within a musical composition
C:the number of flats and sharps in a composition
D:
two notes that are a certain distance apart

D: two notes that are a certain distance apart

In music theory, an interval is the distance between two pitches. It is defined by the number of scale steps and the specific distance in terms of semitones or tones between the two notes. Intervals are foundational to the structure of scales, chords, and melodies.