Musical tone

Physical basis

Physically, many musical tones are produced by vibrating objects that create pressure variations in air or other media. A pure tone is well approximated by a single sinusoidal vibration at one frequency. Most musical sounds are complex tones, consisting of a fundamental frequency and a set of additional frequency components (partials or overtones). Interactions among these components determine the tone's spectral balance and temporal behaviour.

Characteristics and perception

Key attributes used to describe tones include:

• Pitch: the perceptual attribute that orders tones from low to high; closely related to frequency and often discussed in musical contexts as pitch.
• Loudness: the perceived intensity of a tone; psychoacoustic loudness depends on frequency content and level, see loudness for measurement and perception.
• Timbre: the spectral and temporal qualities that distinguish two tones with the same pitch and loudness; sometimes called tone color or timbre.
• Duration and envelope: the time course of a tone, including its attack, sustain and decay, which strongly influence perception and instrument recognition.

Types and modulation

Beyond the simple/complex distinction, tones vary by periodicity and harmonic content. Harmonic tones have partials at integer multiples of a fundamental and often sound pitched and musical. Inharmonic tones contain components that are not simple whole-number multiples and are common in percussion. Musicians further modify tones with vibrato, glissando, articulation and transient noise to create expressive effects.

Musical context and use

Tones are the building blocks of melody and harmony: sequences of tones form melodies, simultaneous tones form chords, and combinations of timbres produce orchestral color. Written notes are symbols that indicate intended pitch and duration, but performers realize those notes as tones with particular loudness, timbre and articulation. Tuning systems and temperament influence how tones relate to one another in scales and harmony.

Production and technology

Instruments, the human voice and electronic systems each produce tones by different mechanisms. Synthesis methods such as additive, subtractive and frequency modulation deliberately combine simple components to shape complex tones. Recording and amplification allow precise control over tone attributes and have expanded composers' and performers' expressive palette.

Terminology and distinctions

In common usage "tone" can overlap with related words. "Note" commonly refers to a notated or conceptual pitch and duration; "timbre" isolates color from pitch and loudness; and "noise" generally denotes a lack of clear periodic structure. Understanding these distinctions helps in analysis, instrument design and music performance.