There are various definitions of music. Eastern and Western musical traditions are very different from one another, and it is hard to define a genre like jazz with the same meaning as, say, military music. That said, most musicologists accept that there are three essential aspects to music. These are rhythm, pitch, and harmony. On top of this, you could easily add other common elements such as timbre, the way a particular sound is perceived. To some people, music also has a visual element, and you can literally dance rather than simply move to its sound. From ancient times, both voices and musical instruments have been used to produce music and, these days, it is a folk art form as well as being a multi-billion dollar global industry.