People's lives have always included music in a significant way. Since the first light of day, there has been music. No one is aware of the discovery or invention of music; researchers may have discovered information about the instruments, but not the music; melody itself. There is too much information about music to be written down, but some people will stop at nothing to plunge into the depths of learning about the history of music. Music is a kind of art that combines vocal or instrumental sounds for aesthetic beauty or emotional expression, typically in accordance with cultural norms for harmony, melody, and rhythm. The simple folk song and the intricate electronic composition both fall within the umbrella of music. Both have been conceptually and acoustically constructed by humans, and both may be found in music of all genres and from all eras of history.