Parts of the Trumpet and their Influence on Sound http://www.molevalleymusic.co.uk/Anantomy2.jpg The mouthpiece, bell, and valves together are the elements that make it possible to produce the full chromatic scale as well as the  rich sound characteristic of the trumpet.   The Mouthpiece Besides providing a comfortable place for the lips to vibrate, the mouthpiece allows the instrument to play the full harmonic series by bringing down the resonances. As explained on the previous page, a closed cylindrical air column produces standing waves at the fundamental frequency and at odd harmonics. The specially engineered tapered mouthpiece however effectively causes the length of the tube to be greater which lowers the high resonant frequencies while leaving the lower frequencies alone. This makes it possible to reach the other harmonics. There are many different types of mouthpieces because the shape and length of the mouthpiece's throat changes the sound it produces. http://hyperphysics.phy-astr.gsu.edu/hbase/music/brassa.html#c1   The Bell The bell does the opposite of the mouthpiece. The flaring raises the lower resonances towards the harmonic series. The overall length is shortened so the high resonances are left alone. While it doesn’t affect the resonances, the shortening of the bell also allows the higher resonances to radiate out more, which is why higher notes often sound louder than the lower ones. The bell also produces a petal tone, which is the note at the fundamental frequency of the harmonic sequence of the instrument. This note is different from the resonant frequency of the air column. The lowest resonance is unused, but if a player vibrates at this frequency, the other harmonics help produce a fictitious fundamental pitch.             http://hyperphysics.phy-astr.gsu.edu/hbase/music/brassa.html#c1   Valves With the bell and mouthpiece alone, it is nearly impossible to reach the full chromatic scale, which is why valves were added. The three valves of the trumpet add certain lengths of tubing which lowers the overall pitch. The first lowers the pitch by a tone, the second by a semitone, and the third by three semitones. When the valves are up, the holes allow the air to go straight though as though it were just a long length of tube. When pressed down, however, a different path of tubing is opened, adding to the length the air has to travel to get to the end. The frequency of an air column is inversely proportional to length, which allows us to figure out how each valve affects the resonance. With the adjustments made by the mouthpiece and the bell, the valves fill in the rest of the chromatic notes producing the full scale. Each of the lengths of tubes attached to the valves can also be adjusted, lengthening or shortening the tube. This allows players to tune their instruments.               http://library.thinkquest.org/10693/media/anivalve.gif                                                  http://hyperphysics.phy-astr.gsu.edu/hbase/music/trumpet.html#c1 Home History General Physics The Harmonic Series Parts of the Trumpet Bibliography