What is the main characteristic that differentiates a major scale from a minor scale?

The distinguishing characteristic that separates a major scale from a minor scale lies in their overall sound quality, often described in emotional terms such as happy or sad. A major scale is typically perceived as bright, cheerful, and uplifting due to its specific pattern of whole and half steps, which creates a consonant, stable sound. In contrast, a minor scale produces a more somber, melancholy, or introspective tone because of its distinctive scale structure, which incorporates a lowered third degree compared to the major scale. This shift in the third degree is crucial, as it influences the harmonic and melodic qualities of the respective scales, leading to their association with different emotional expressions in music.

Other options present different aspects that do not accurately define the core difference between major and minor scales. For instance, the speed of the scales, the use of sharp versus flat notes, or the number of notes they consist of do not inherently characterize the major and minor scales. The quintessential emotional qualities of sound remain the key factor in differentiating them.