Timbre is the quality of a sound that lets you tell a violin from a flute, even when both play the same note at the same loudness. It is often called the color of sound because it gives each voice or instrument its unique character. Timbre matters in music, speech, sound design, and audio engineering because it shapes how we recognize and respond to sounds.
Without timbre, many instruments would sound much more alike.
Key Facts
- Timbre depends on the mix of frequencies in a sound, not just the main pitch.
- A pure tone has one frequency, while most musical sounds contain a fundamental plus harmonics.
- Harmonic frequencies follow fn = n f1, where f1 is the fundamental frequency and n = 1, 2, 3, ...
- Waveform shape affects timbre because different shapes contain different harmonic content.
- The envelope of a sound is often described by ADSR: attack, decay, sustain, release.
- Sound intensity level is measured in decibels: beta = 10 log10(I/I0).
Vocabulary
- Timbre
- Timbre is the tone quality that makes two sounds with the same pitch and loudness sound different.
- Fundamental frequency
- The fundamental frequency is the lowest main frequency of a musical sound and usually determines the pitch we hear.
- Harmonic
- A harmonic is a frequency that is an integer multiple of the fundamental frequency.
- Waveform
- A waveform is a graph or shape showing how air pressure changes over time in a sound wave.
- Envelope
- An envelope describes how a sound's loudness changes from the start of the note to its end.
Common Mistakes to Avoid
- Confusing timbre with pitch is wrong because pitch mainly depends on frequency, while timbre depends on the full frequency mix and sound shape.
- Assuming louder sounds have different timbre is wrong because loudness changes amplitude, but the instrument identity can stay the same.
- Ignoring the attack of a note is wrong because the first fraction of a second often gives important clues about the instrument.
- Thinking only one frequency is present in a musical note is wrong because most instruments produce a fundamental plus many harmonics and overtones.
Practice Questions
- 1 A guitar string plays a fundamental frequency of 110 Hz. What are the frequencies of the 2nd, 3rd, and 4th harmonics?
- 2 Two instruments both play A4 at 440 Hz. Instrument A has strong harmonics at 880 Hz and 1320 Hz, while Instrument B has a much stronger 1760 Hz harmonic. Which harmonic number is 1760 Hz for A4?
- 3 A flute and a clarinet play the same note at the same measured loudness, but they still sound different. Explain which sound properties could cause this difference.