What defines rock music and how has it evolved over time?

Rock Music is characterized by its use of electric instruments, strong rhythms, and emphasis on vocals and melodies. It has evolved over time by incorporating elements from various genres such as blues, folk, and pop, leading to the development of subgenres like punk, metal, and alternative rock. The sound of rock music has also evolved with advancements in technology, leading to new styles and experimentation with different sounds and production techniques.