What is a "diatonic scale"?

A diatonic scale is fundamentally defined as a seven-note musical scale that features a specific pattern of intervals resulting in a mix of five whole steps and two half steps. This arrangement provides the scale with a unique sound and emotional quality, differentiating it from other types of scales.

In Western music, the most familiar diatonic scales are the major and natural minor scales. For example, the C major scale consists of the notes C, D, E, F, G, A, and B, comprising the whole and half-step relationships that define the diatonic structure. The distribution of whole and half steps creates distinct modes and allows for various harmonic and melodic possibilities.

The other options do not accurately describe a diatonic scale: a ten-note scale is more complex and not characteristic of diatonic structures; a scale consisting only of flat notes does not conform to the diatonic definition, as diatonic scales can include both sharp and natural notes; and a scale that encompasses all 12 notes of the chromatic scale is fundamentally different, as the chromatic scale includes every note available in an octave, whereas the diatonic scale is limited to seven notes with specific step patterns.