In music, the term “timbre” is used for the quality of a musical note or sound that distinguishes different types of sound production, such as voices or musical instruments. Timbre is also known in psychoacoustics as tone quality or tone colour. There is no rating scale on which timbre can be measured, unlike pitch and loudness, which can be rated on scales from “high” to “low”.(i) The commonly quoted American National Standards Institute formal definition of timbre reflects this: “Timbre is that attribute of sensation in terms of which a listener can judge that two sounds having the same loudness and pitch are dissimilar".(ii) In other words, two sounds that are perceived as being different but which have the same perceived loudness and pitch differ by virtue of their timbre.
Timbre plays an essential role in musical composition and performance. I would like to unfold this with the example of Claude Debussy, one of the most prominent figures working within the field of Impressionist music. Impressionist music put very much emphasis on timbre, creating impressions and emotions. "To a marked degree the music of Debussy elevates timbre to an unprecedented structural status; already in L'Apres-midi d'un Faune the colour of flute and harp functions referentially," according to Jim Samson (1977).
Debussy treated the orchestra according to his own sound ideals, creating a very personal mixture from its traditional components: violins commonly in eight, ten or twelve parts, generous use of harps, woodwind unmixed and seldom used to reinforce other parts, brass veiled and often muted, with very restrained use of trumpets and trombones.
He uses the low notes of the flute to express anguish or melancholy, and likes to give solos to harps and percussion. For Debussy the bassoon tends to become a vehicle for dramatic expression. His experiments with sonorities were also directed towards individualization of timbres. Working in 1894 on an early version of the three