What aspect of singing does resonance affect?

Resonance plays a crucial role in shaping the quality of a singer's sound, directly influencing its clarity and fullness. When a singer produces sound, the vibrations travel through their vocal cords and resonate within the vocal tract — including the throat, mouth, and nasal cavities. This resonance enhances certain frequencies and contributes to the overall tonal quality of the voice. A well-resonated voice typically sounds richer and more vibrant, making it clearer and fuller to listeners.

Clarity ensures that the notes are distinct and easily understood, and fullness gives the voice a robust character. This combination is essential for effective singing, as it allows the performer to convey emotion and connect with the audience. In contrast, the other aspects mentioned, such as speed, harmony complexity, and volume, relate to different vocal techniques or musical concepts that do not directly involve how resonance influences sound quality.