An example of timbre is the distinct difference in sound between a trombone and a piano playing the same note at the same level of intensity. Timbre, also called tone color, is the characteristic quality of a sound produced by a particular instrument, independent of pitch or loudness.
Timbre is a complex sound quality, created mainly out of the harmonics, vibrato and the attack and decay of a sound. Harmonics are frequencies at which an instrument produces a sound vibration in a standing wave pattern. The regular, repetitive sound of the standing vibration is perceived as more pleasing than irregular vibrations. Vibrato is a periodic change in tone, such as is heard in warbling singers. Attack and decay are how quickly or slowly a sound begins and ends. These characteristics produce timbre because they differ from instrument to instrument based on the its physical material, size, structure and method of producing sound.