Art of combining sounds into a structured form, usually according to conventional patterns and for an aesthetic (artistic) purpose. Music is generally divided into different genres or styles such as classical music, jazz, pop music, country, and so on.
Music education in the schools during the past 5 decades has witnessed a continuous transformation in curriculum content, scheduling, its function in academia, as well as course offerings. Several key events have played a role in this transformation.
A branch of music scholarship that studies the materials and structure of music. Music theory deals with the properties of single sounds—pitch, duration, timbre, dynamics, tuning, and temperament —as well as those of collections of sounds, intervals, consonance and dissonance, scales, modes, melody, counterpoint, harmony, rhythm, themes, meter, form, texture, analysis.
Music is such an important part of life that some find it difficult to imagine what the world would be like without it. Music is a part of many social activities and is present in much of our environment. People may use music to communicate with others and often respond emotionally to music. Music has been a part of all cultures, and people report listening to music more than any other activity over a wide variety of contexts.
The Faber Companion to 20th Century Popular Music by 
Opera: The Great Composers and their Masterworks by 
Music Theory Secrets by