Music (Middle English musik, from Anglo-French musike, from Latin musica, from Greek μουσικη mousike) is an art form consisting entirely of organized sound interspersed with periods of silence. It takes its name from three Greek goddesses known as the Muses, who specialized in stimulation of an artist's or poet's mind. It is the highest of all the arts, and the one best able to stir human emotion. Depending on what sort of work of music one composes, interprets, or hears, it can build a person up in spirit, or lead him into very challenging temptation. It is the art form to which the Bible gives its strongest endorsement, and to which the Bible pays the greatest attention.
Strictly speaking, music means sound having any organization at all, while noise is purely random sound. But the roots of these two words suggest that music ought to mean that which makes one think and feel something new and significantly different, while noise (from the same root from which we get the verb I annoy) is merely a distracting, disturbing, or often physically damaging sound. Some modern composers have attempted to stretch the definition of music by using noises in a manner that they insist is organized. Whether such a work product properly falls under the heading of "music" is beyond scope here.
Note that music is not limited to such sounds that a human being might produce by fashioning an instrument for the making of a simplified or otherwise organized sound and then "playing" said instrument. The chirping of birds and certain insects may properly be called music, especially if the sound produced is particularly pleasant to the listener. Furthermore, some of the most sophisticated music attempts to imitate the sounds made by birds, insects, and other animals.
The earliest post-diluvian records of music have been found in Iraq and India, and date at least from the time of Abraham. They probably were made shortly after the Babel Incident. Almost every culture and religious movement has its own particular form of music. Some forms are richer and more sophisticated than others.
The Hebrew people, and especially the children of Israel, have some of the grandest of all musical traditions. Mentions of "singing to the Lord" abound in the Old Testament. The most highly specific testimony to the power of music over human emotions is surely contained in the story of King Saul and how he came to recruit the young David as his armorbearer and personal musician. I_Samuel 16:14-23
King David, at the height of his reign, once had a four-thousand-voice choir to assist in the worship of God. The Book of Psalms is in fact a collection of lyrics for some of the first worship songs in Israelite tradition. (Most of these came from David, but at least one comes from Moses.) The Song of Solomon is a grand ballad of love that most scholars regard as a type of the love of Jesus Christ for His elect.
The Greeks, when Alexander the Great accepted the surrender of Jerusalem in his wars of conquest, introduced their own brand of music to the region--which the Jews largely resisted. But music was highly prominent throughout the Greek world--and later in the Roman world following Rome's conquest of Greece. The Greeks' contributions to musical theory influenced the classical artists for centuries to come, and still influence those composers who prefer to adhere to the classical traditions of music.
The earliest Greek music was associated with Greek theater. But beginning with the fall of Rome, music became largely liturgical. The primary influence remained the Roman Catholic Church until the twin movements of the Renaissance and the Reformation, each of which introduced a countervailing tradition.
From that time forward, most scholars divide music into "classical" music (composed primarily to achieve a high art) and "popular" music (composed for the masses in the primary hope of financial remuneration). In the former category one can usually find music composed for these purposes:
- As an aid to worship, by placing the listener into a proper frame of mind for worship or instill in the listener a proper appreciation of the grandeur and glory of God and of the listener's own place in relation to Him.
- To rally troops, either during training, on the march, or in battle.
- To celebrate military victory or the reign of a king, usually the one presently on the throne.
- Occasionally as a supplement to various forms of theater. Originally (especially in the Greek era) this meant the open-air live theater of classical fame. Today such music might accompany a live stage performance or several scenes in a motion picture.
Popular music, on the other hand, is almost always used:
- For entertainment, and more particularly for financial remuneration.
- As a powerful aid to propaganda.
- Very frequently as a supplement to modern theater in all its forms, including stage, motion pictures, and especially television.
Possible healing effects
The recent case of a choir consisting primarily of sufferers from various neurological diseases and some of their caregivers, friends and associates, has highlighted recent evidence that performing music, or even listening to it, might actually help to heal the brain, in addition to providing helpful emotional support to the disease sufferers. Music appears to stimulate the brain to find supplemental neural pathways to route around a region of damage. Benefits have been observed in patients suffering from stroke, Parkinson's Disease, and other degenerative neurological disorders.
Power over emotion
As stated above, music has a very powerful effect on human emotion. Music relies on sound, and if "faith comes through hearing," then so does emotion.
In 1973, the amateur botanist Dorothy L. Retallack claimed that music has an effect on plants that are placed within range of its waves. This effect, she said, depended upon whether the music evokes positive emotions (e.g., joy or contentment) or negative emotions (discontentment, frustration, anger, horror, etc.) in most human hearers. "Positive" music makes plants flourish and even "reach" for, or grow toward, such music. Negative music causes plants to "recoil" (grow away) from the music, and prolonged or repeated exposure debilitates and eventually kills plants.
No other botanist has ever confirmed Retallack's findings. But the effects of music on animals and man have been documented far more extensively. Indeed, commercial enterprises always attempt, at great expense of time, money, and effort, to find and deploy forms of music that will enhance worker productivity or cause prospective customers to behave in a manner calculated to make them purchase their goods and/or services. For example, operators of supermarkets routinely play the form of popular music called "rock and roll," with its four-quarter backbeat that emphasizes the third beat rather than the first, because such music induces the listener to move and even to march to that rhythm.
More sophisticated examples exist in theater. This is especially true of the performing arts called opera and ballet, but applies also to the use of music as an adjunct to a theatrical production, whether on the stage, as a motion picture, or as a television show. The most dangerous uses of music are clearly in propaganda, in which the propagandist seeks to manipulate people's emotions and stir them typically to rage and hostility against those groups or causes that the propagandist opposes.
More hazardously yet, music can strengthen in the listener a curiosity about, or even a desire for, an act of sexual or other sin. Sadly, this use of music is probably as old as "the oldest profession." Cultural critics observe, pointedly, that permissive cultures have permissive music, and non-permissive cultures avoid such music.
Yet for all this, music is still important in worship. If it were not, then it would not have received the favorable attention that the Bible clearly gives to it. As powerful a force for evil as it might be, music can be an equally powerful force to encourage the listener to worship, appreciate, and above all obey God and keep His laws--at least, as best as any human being is able.
Music is not neutral
For a detailed explanation of that statement, see Essay:Music is not neutral.
Traditions and principles for liturgical music
Saint Paul specifically exhorts his readers to employ music, and specifically "psalms, hymns, and spiritual odes," to bring them closer to God. (Ephesians 5:19 , Colossians 3:16 ) Here the term psalms includes not only the specific chapters in the Book of Psalms, but also any song that primarily quotes Scripture. Hymns are songs primarily of praise and magnification of God. Spiritual odes are primarily personal testimonies, either of salvation or of one's own perception of God. (Amazing Grace, by John Newton, is a particularly popular example.)
The Rev. Alan B. Brown, MDiv, ThM, states that liturgical music ought to satisfy three prime tests:
- Accuracy, mainly of the lyrics, either as quotes of Scripture or reflections of Christian principles
- Associability of the lyrics and/or the notes with Godly things, as opposed to worldly things
- Appropriateness of the lyrics and/or the notes to the setting in which one proposes to sing or play them
Sadly, no manuscripts survive that contain the notes to any specific tunes that might have been current in Biblical times. However, the titles of many of the Psalms contain specific instructions, originally to the music director at King David's court, as to the type of tune to which the words were set and the types of instruments to accompany the words.
Controversy concerning liturgical music for today
The selection of music for worship in church has often split churches. Many clergymen (including both ministers and deacons/elders/wardens/vestrymen) and also many laypeople prefer to sing their hymns to music written in the classical style. Others prefer their music in the modern style.
That all music was once contemporary to the time wherein it was composed, follows logically from the very nature of time. Nevertheless critics of "contemporary Christian music" often assert that such music does not bring glory to God and does not serve the proper purpose of worship, which is to separate the believer from influences that would serve to move him away from thinking on Godly things. To paraphrase Brown, such music fails the triple tests of accuracy, associability, and appropriateness. As evidence, these critics point out that the musical styles of contemporary "hymns," and also the costumes and other trappings of the most famous touring performers of such works, differ but little from those of the "American Top Forty" artists (meaning the forty largest generators of revenue among contemporary popular American music performers). Such styles are typically garish and ostentatious, and some find them vulgar as well.
Defenders of the contemporary style, on the other hand, assert that they are merely repeating Jesus' practice of dining often with the outcasts of the Jewish society of his day, including, of all people, Jewish publicani who helped collect Rome's crushing taxes. But this argument is probably flawed because the issue involves how to place someone in a proper frame of mind for worship, and whether a form of music not normally associated with instilling a proper fear of God is as readily adaptable for that purpose as its defenders assert.
Defenders of contemporary "worship" music sometimes assert that music per se is amoral, i.e., devoid of moral content or message. But the developers of the "rock and roll" genre have explicitly stated, and often, that their music is an expression of rebellion against the authority and traditions of their parents' generation, and against authority and tradition in general.
Significance of Music for the Theory of Evolution
Most scientists agree that it is difficult to explain music according to theories of evolution, because music is abstract and difficult to test. Although many scientists speculate, they admit that no theories put forth are any more than 'just so' theories. 
Researchers in the journal Science acknowledge that "music remains a mystery" and state that the biggest question is, "what evolutionary purpose does music serve?"  Other science authors state that music is "'auditory cheesecake,' a byproduct of natural selection that just happened to "tickle the sensitive spots" of other truly adaptive functions, such as the rhythmic bodily movements of walking and running, the natural cadences of speech, and the brain’s ability to make sense of a cacophony of sounds."
Other research suggests that the penchant for music originated with humans, because monkeys show no reaction or preference to consonance (the harmonic organization of music). 
- Hooper S, "Music a 'mega-vitamin' for the brain," Cable News Network, 2 June 2009. Accesssed 3 June 2009. <http://www.cnn.com/2009/HEALTH/06/02/music.therapy/index.html?eref=rss_latest>
- Music defined in the Merriam-Webster Online Dictionary.
- Music by Wikipedia
- History of music by Wikipedia
- About Positive and Negative Music from the Dovesong Foundation.
- Retallack, Dorothy L. The Sound of Music and Plants. Devorss and Company, June 1973, 96 pp., paperback. ISBN 0875161707
- Linking Sexual Music and Teen Behavior by Gene Edward Veith at the World Magazine Blog
- Brown, Alan B.: telephone interview conducted on 1 March 2007 with user Temlakos