Timbre – why violin and flute sound different
If a violin and a flute play the same note, equally loud and equally long, we still tell them apart effortlessly. What we hear there is the tone colour – in the technical term the timbre. It is the building block that gives a sound its unmistakable character, before melody or harmony even begin. Often we recognise an instrument from a single note – timbre is, as it were, its fingerprint.
What makes timbre audible
The reason for timbre lies in the physics of sound. An instrument never produces only a single vibration but a fundamental and above it a whole series of softer overtones. Which of these overtones sound along, and how strongly, differs for every instrument – and it is precisely this mixing ratio that our ear perceives as "colour". The clarinet emphasises different overtones than the trumpet, which is why the one sounds soft and hollow, the other radiant and cutting, although both can play exactly the same fundamental.
Just as important is the sound's course over time, especially its beginning – the onset transient. The brief moment in which a note comes into being (the plucking of the string, the striking of the key, the puff of air of the flute) contains many characteristic noise components. You can test this strikingly: cut away the very first fraction of a second from a recording and a piano suddenly becomes hard to recognise as a piano. The beginning carries a large part of the identity.
The instrument families
Instruments are ordered into families by the way they produce their sound. In the string instruments (violin, viola, cello, double bass) the bow sets a string vibrating – warm and singing. In the wind instruments a column of air vibrates; one distinguishes woodwinds (flute, clarinet, oboe, bassoon) and brass (trumpet, horn, trombone, tuba). In the percussion instruments a strike produces the sound, sometimes with a definite pitch (timpani, vibraphone), sometimes without (drum, cymbals). And the keyboard instruments such as the piano combine mechanism and string. Each family has its own basic colour, and within each family each instrument has its own character once again.
Timbre as a means of expression
Composers use timbre deliberately to paint moods. The same melody seems intimate and sustained on the cello, bright and agile on the piccolo, rough and distant on the muted trumpet. The art of assigning the different instruments their voices and blending their colours is called orchestration – it is, as it were, the painting of music. Even a single instrument can change its colour: a violin through a different bowing or a mute, a guitar through the point of attack near the bridge or over the fingerboard.
The same instrument, different colours
An instrument has not just one timbre but many. In different pitch ranges – the registers – the same instrument often sounds astonishingly different. The clarinet, for instance, is dark, hollow and a little mysterious in the low range, warm and round in the middle, bright and penetrating up high – musicians positively speak of different "colours" of one and the same instrument. The human voice knows this too: the chest voice sounds different from the head voice. Composers therefore choose a register not only by the pitch needed but deliberately by the colour they need at that point. Whoever places a melody consciously in a particular range always makes, thereby, a decision about its character.
New colours through combination
Perhaps the greatest art of timbre lies in blending. When two instruments sound together, the result is not simply the sum but a new colour that neither could produce alone. A flute playing the same note an octave above a clarinet merges with it into a sound whose origin one can barely pick out any more. Such blended sounds are the real craft of orchestration: the composer paints not with pure colours but mixes them like a painter on the palette. A warm string sound to which a clarinet gives fullness; a brass texture grounded by timpani – only through these combinations does the rich, many-layered sound arise that we admire in an orchestra. In electronic music this principle goes even further: here timbres can be freely invented by building up overtones deliberately, instead of taking them from an existing instrument.
Hearing timbre consciously
To perceive timbre a simple exercise helps: hear the same familiar melody in different versions and attend to how the character changes through the instrument alone – even though notes and rhythm stay the same. Whoever additionally tries, while listening to music, to pick out and name the instruments involved trains their ear quickly. In time you recognise not only the families but the individual voices – and suddenly hear a piece far more colourful and dense. A second exercise trains the ear for blended sounds: with a full orchestral sound you try deliberately to "pull out" individual instruments and follow them while the others play on. At first everything merges into a surface, but gradually the voices step apart like colours in a painting that you at first perceive only as a whole and then in their nuances. It is precisely this differentiated listening that turns passive hearing into active discovery – and makes timbre perhaps the most sensuous of the seven building blocks.
From the moment to the whole
Rhythm, melody, harmony, dynamics and timbre shape the single moment. How these moments are ordered into a meaningful whole is shown by the next building block.