Every single sound you hear has DURATION.  Duration is the second element of sound.  A percussive sound has a very short life, whereas the drone of a large organ pipe will last as long as the organist keeps his foot on the pedal, as well as what is created by room reverberation.  Often mistakenly called "echo", "reverb" is a  part of a sound's duration that cannot be controlled by the player.  After the initial sound has stopped, tiny reflections occur in the space that the sound is heard, causing a wash of remaining sound that eventually fades away as the sound energy is absorbed and dissipates.  Reverberation can be a good thing;  it can make a thirty piece orchestra sound like sixty.  Conversely, too much reverb can cause problems such as reduced intelligibility, muddiness, and distortion of timing and rhythm.

Topic: Essential Elements 4