User Manual

ARTURIA – BRASS 2 – USER’S MANUAL

8 RESEARCH

8.1 Trumpet and Trombone

8.1.1 Trumpet

8.1.1.1 How does it work?

The trumpet is a wind instrument in the brass family, composed of a mouthpiece and a

curved brass tube/cylinder that uses three valves to change the length of the tube, and

therefore the selection of notes that the player can choose. In the condition where sound

is formed to create a note with a well defined frequency, operation of the trumpet can be

described as the synchronization of several oscillations or waves at the same frequency:

the oscillation and vibration of the lips of the trumpeter (which open and close, for

example 440 times a second for the A of tuning fork), the waves of pressure in the

interior of the mouth and lungs flowing into the instrument, and then from the

instrument outward to create a musical sound (to be heard by the ears of listeners). This

common frequency allows the ear to distinguish notes played from each other (each note

corresponding to a particular frequency).

8.1.1.2 A little musical physics… a little instrumental practice…

When a trumpeter wants to play a note, he presses his lips together, increases the air

pressure in his mouth and lungs, and contracts his diaphragm (the muscle allowing

inhaling and exhaling). If the pressure is strong enough, the lips open temporarily and a

puff of air escapes into the mouthpiece. The acoustic disturbance generated by this small

release of air at the opening of the lips spreads out along the instrument and is refracted

through the internal sections of the instrument. Thus, one reflected wave brings back the

energy necessary to the lips in order to develop and eventually sustain the oscillation.

When the resonance frequency from the lips (the frequency at which the lips would

vibrate if the instrument wasn’t there) is close to the frequency of instrument resonance

(the frequency at which the internal pressure oscillates if the lips were not there), the

exchange of energy is constructive and allows a note to develop.

As with other brass instruments, the production of trumpet sound depends on the

cooperation between the lips of the musician and the instrument. The frequency of

oscillation (thus the sound!) is at the same time controlled by the instrument resonance

and the frequency of the lips. Thus, two possibilities are presented for the trumpeter to

choose a note:

• The trumpeter can increase or diminish the frequency of sound by modifying his

embouchure (the embouchure is what we call the ensemble of lip and face

muscles used in playing an instrument). In practice, he stiffens his lips to increase

the resonance frequency. It is like this that the trumpeter can produce different

notes with the same fingering. It is the bugle principle which, even without a

valved instrument, allows one to play all the notes in a harmonic series. Try to

modify the “pitch” parameters in BRASS 2 and you will obtain the exact same

results.

• The changing of a note can equally be achieved by increasing/diminishing the

resonance frequency of the instrument. One needs only to modify the position of

the three pistons. By pushing the pistons one increases the length of the pipe that

the trumpet is made of and in effect lowers the resonance frequency. Pushing the

n°1 piston lowers the frequency one half step, n°2 one full step, and n ° 3 one

and a half steps. The effect is increased when you press several pistons