Music theory is the study of how music works. It examines the language and notation of music. It seeks to identify patterns and structures in composers’ techniques across or within genres, styles, or historical periods. In a grand sense, music theory distils and analyzes the fundamental parameters or elements of music—rhythm, harmony (harmonic function), melody, structure, form, texture, etc. Broadly, music theory may include any statement, belief, or conception of or about music. A person who studies these properties is known as a music theorist. Some have applied acoustics, human physiology, and psychology to the explanation of how and why music is perceived.
Music has many different fundamentals or elements. These include but are not limited to: pitch, beat or pulse, rhythm, melody, harmony, texture, allocation of voices, timbre or color, expressive qualities (dynamics and articulation), and form or structure. In addition to these “fundamentals,” other important concepts are employed in music both in Western and non-Western cultures, including “Scales and/or Modes” and “Consonance vs. Dissonance.”
Pitch is a subjective sensation, reflecting generally the lowness (slower wave frequency) or highness (faster wave frequency) of a sound. Most people appear to possess relative pitch, which means they perceive each note relative to some reference pitch, or as some interval from the previous pitch. Significantly fewer people demonstrate absolute pitch (or perfect pitch), the ability to identify certain pitches without comparison to another pitch. Human perception of pitch can be comprehensively fooled to create auditory illusions. Despite these perceptual oddities, perceived pitch is nearly always closely connected with the fundamental frequency of a note, with a lesser connection to sound pressure level, harmonic content (complexity) of the sound, and to the immediately preceding history of notes heard. In general, the higher the frequency of vibration, the higher the perceived pitch is, and lower the frequency, the lower the pitch.