Which texture involves all voices singing the same rhythm and results in a blocked chordal texture?

The answer is homorhythmic texture, as this term specifically describes a musical texture where all voices or parts sing or play the same rhythmic pattern, creating a uniformity in their delivery. This results in a blocked chordal texture, meaning that the harmony is presented all at once, with all parts moving together rather than independently. This approach to texture is often used to create a rich and cohesive sound, emphasizing harmony over counterpoint, which is more common in other types of textures where different voices may move to different rhythms.

Classical music, while it may include examples of homorhythmic texture, is a broader term that encompasses a wide variety of styles and textures, some of which do not fit this specific description. Absolute music refers to instrumental music that does not attempt to convey a narrative or represent something outside of itself, which does not pertain to the characteristics of vocal texture. Lastly, melodic structure deals with the arrangement of melody within a piece of music, which is not directly related to the group rhythmic alignment that defines homorhythmic texture.