Music permeates every culture. Despite its diverse and often contradictory forms, it unites the world in a shared quest to channel sound into meaningful aesthetic forms that express beauty, identity, values, emotion, and community. Musicians, philosophers, psychologists, and theologians have long sought to explain its universal appeal. But attempts to rationally define and categorize musical genres, styles, or effects are doomed to failure; they neglect the visceral, emotional power of music and its ability to act on people in ways that are personal and unique.
From the earliest times, human cultures have incorporated sound into their social and religious life. From ceremonial and folk rituals, to secular festivals, music provides an outlet for expression of emotions, ideas, and ideals. Music also lends itself to alliances with spoken words, such as songs, and with physical movement, such as dancing. In a variety of media, music has been used to strengthen political leaders, sell cars, foment revolutions, and convert souls.
The ancient Greek philosopher Plato emphasized that the experience of music was an emotional and functional experience that engaged both the hearing and the intellect, with individual tones taking their place within larger formal units. His pupil, Aristoxenus, a follower of Stoicism, emphasized the importance of sensation and rejected the dominance of mathematical and acoustical considerations, but he also stressed the role of music as an accessory to speech.
Aristotle, Confucius, and Martin Luther endorsed the Platonic-Aristotelian view of music, with the latter emphasizing that its use was restricted to moral and spiritual activities. Later Protestant reformers, such as John Calvin (1509-64) and Henry VIII, were more conservative in their view of music, warning against voluptuous or effeminate music and insisting that the text should be given primacy.
Since the 19th century, technological advances have democratized both music production and listening. Edison’s phonograph with wax cylinders, radio, the vinyl LP record, cassette tapes, compact discs, and digital MP3 audio encoding have made music more available to listeners than ever before.
The most important element of any song is its melody, which should complement the chord progression and convey a particular mood. Melody writing can be as simple or complex as the composer wants. Many artists start with a title, lyric, or subject in mind, and play around with chords and melodies until they find something that fits. They may also experiment with the rhythmic feel or tempo of the song, using meter and tempo changes to organize it. Other elements that can add meaning or emotion to a melody are its rhythm, timbre (the distinct quality or color of a sound), and texture (how the parts interweave—monophonic, homophonic, or polyphonic). The use of articulation, dynamics, and other expressive techniques help musicians communicate emotions through music. In addition, the key of a piece can be used to set the tone for the music—major keys are usually uplifting, while minor keys have a melancholy or emotional quality.