Which statement is true regarding the rules of harmony in jazz prior to modal jazz?

The statement that all previous styles followed the same rules is accurate because, prior to modal jazz, jazz harmony was largely characterized by a consistent set of conventions and principles. In the earlier eras of jazz, such as swing and bebop, musicians adhered to established harmonic frameworks, which typically included the use of chords, progressions, and functional harmony derived from Western classical music. This foundation included common chord changes, like the ii-V-I progression, and a focus on the resolution of tensions within a given key.

As music progressed toward modal jazz, innovations began to challenge these established norms, allowing for different approaches to harmony, but prior to that shift, a strong sense of structural coherence across various styles maintained a commonality. This shared adherence to harmonic rules provided a cohesive language that jazz musicians utilized in improvisation and composition, which is essential for understanding the evolution of jazz harmony leading up to the modal era.