We can define "music" more formally as a series of organized sounds and silences temporal in nature, which those who know it can reproduce.
All music also has some varying degree of rhythm, melody?, and harmony?. Though the scales which arose in the world's various [musical tradition]?s are often quite different, the frequency of the notes in a given scale are usually related by some simple [mathematical law]? Scales are eight notes starting on one given note and working its way up to the first octave of the starting note, journeying through whole and half steps. Scales can begin in any key and to stick with the whole-whole-half-whole-whole-whole-half format, accidentals are placed on certain notes to achieve the format. For instance, consider the math of Western music scales. The early music of Greek antiquity further developed the scales to the notion of modes, where each mode is the usual diatonic scale but with a different starting note. Modes would come back into favour some time later in the development of jazz and more contemporary 20h century music.
Closely related to melody but a much newer development is harmony?. Harmony is the sound made by two different notes played at once, whether on one instrument such as a guitar or piano or the intersection of two or more [musical line]?s on distinct instruments, such as in a fugue.
For much of the history of western classical music the conventions and rules of harmony were strictly enforced, often by the controlling influence of the Church, whilst folk music and non-Western music also developed often widely different notions of harmony. Church music was controlled by the churches in the Baroque and Classical periods, many hymns being written for the daily masses.
The following are music-related topics:
The academic study of music is called Musicology.