Final answer:
Jazz-rock-fusion music in the 1970s evolved by blending jazz improvisation with rock rhythms, resulting in a new hybrid genre that combined the improvisational aspects of jazz with the energetic beats of rock music.
Step-by-step explanation:
Jazz-rock-fusion music evolved in the 1970s by blending jazz improvisation with rock rhythms. This style of music emerged as musicians began experimenting with the electric instruments, incorporating elements from various genres such as gospel, blues, country, jazz, and R&B to form the new sound of rock and roll.
Jazz-rock fusion became a prolific ground for improvisation similar to jazz but was backed by the strong, steady beats of rock music. In the 1970s, this hybrid genre gained popularity as it brought together the complexity and spontaneity of jazz with the energy and appeal of rock music.
While classical music has influenced many genres, its impact on jazz-rock fusion was not as direct as the combination of jazz and rock elements. Similarly, folk music integration and electronic dance beats were not predominant forces in the evolution of jazz-rock fusion during the 1970s.