Pluck, blow,
strike, bow


Discussion - What does an envelope look like?

If you are in France and mention 'enveloppe' and 'timbre' in the same sentence you will be handed an envelope and a postage stamp. Say 'merci' and go write your letter. This postage envelope  has nothing to do with the topic of timbre. 

On the other hand...

The sound envelope  - Attack,  Decay,  Sustain,  Release - is how the intensity or strength of a sound varies with  time.

The ADSR envelope can create sounds that have an initial tonguing  sound or click.  For example you might hear the click of the plectrum on  the string at the start of the note when an acoustic guitar is playing.

Study the following rough diagrams of envelopes formed by

  1. a piano (struck string)
  2. a gut-string harp; a guitar (plucked string) and
  3. a violin (bowed string).
  4. an oboe (blown)



gut harp wav file
string harp

guitar wav

In this extract there is a certain amount of vibrato which adds richness and depth to the timbre. Is vibrato the same as tremolo?

bowed violin wav

Vibrato - link 1

Vibrato - link 2

  1. Look at the envelopes that occur when an oboe plays an ascending chromatic passage from A#3 to F6 (Middle C = C4)

  2. Listen to the MIDI example.

The character of a sound is greatly affected by the harmonic content  but the timbre is also affected by any changes in level and pitch while the sound is heard.  The word 'envelope' describes these changes.


  1. There are instruments being plucked, blown and struck in this piece of Jazz.  Can you name them?  Which method of sounding a note is not represented here?
  2. You'll hear the missing one in the next extract by Bach.


Now it's your turn to experiment with timbre.

Find out by using real examples how to change the timbre of music by tampering with the envelope.
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