Popular music is generally defined as either works created by the masses--i.e., modified by a series of contributors over time as in the case of the folk tradition--or material created by specific composers with the aim of achieving widespread acceptance (large record sales, high television ratings or large concert turnouts when performed, etc.). In contrast, serious music (also termed art or classical music) represents work created to please the specific needs of the particular composer rather than to please the general listening public. Most classical composers would readily admit that they have nothing against commercial success; however, this popularity must never come at the expense of artistic expression. The differing circumstances at the core of the music-making process don't necessarily have any bearing on the quality of the music produced. Excellent popular music can result from the initial impulse to generate a best-selling record, whereas the finest instincts to leave a masterpiece for posterity may lead to nothing more than an empty academic exercise unappreciated by anymore other than, perhaps, the composer.
All music is comprised of certain elements that can be discerned by any listener who possesses a basic understanding of the art form. Recognition of how these elements are employed by composers and musicians can further enhance one's appreciation of music.
Individual notes, whatever their pitch or volume, vary in general quality of sound, depending on the instruments producing them. This concept is known as "tone color" or "timbre," and can be described through the use of terms like warm, vibrant, brittle, brassy, muddy, etc.
Rhythm designates the time strictures of a musical work. Time is comprised of a succession of beats; the particular arrangements of long and short notes represent rhythms. An "accent" denotes those beats that are more emphatic than others. With most popular forms of music, a recurring rhythmic pattern can be discerned; each occurrence of a repeated pattern--consisting of a principal strong beat and one or more weaker beats--is known as a "measure" or "bar."
The performing of a succession of musical pitches according to a particular rhythm results in "melody." Of all musical elements, melody is likely to interest listeners to the greatest degree, often evoking strong emotions and sentiments. Melody can be effectively used to maintain interest in a work, as the listener waits to find out how the melody line works out. Groupings of simultaneous pitches are referred to as "chords." A melody is considered to be "harmonized" when supplied with a successive array of chords.
Music is also comprised of thematic material that varies in length and other characteristics. In a speech, the "themes" would be the main points elaborated on by the speaker. Musical notation can be developed in much the same way.
The blend of various sounds and melodic lines occurring simultaneously in a piece of music is called "texture." Whereas melody is perceived in the horizontal dimension, texture exists in a vertical framework.
These musical elements will be noted throughout the text in reference to particular qualities of the popular music styles being discussed. It is the unique combination of these elements which gives each musical genre--and, more specifically, each song--its own identity.