The diameter of the bore affects qualities such as available harmonics, timbre, and pitch stability how far the player can bend a note in the style required in jazz and other music. The bell at the bottom of the clarinet flares out to improve the tone and tuning of the bottom notes. The fixed reed and fairly uniform diameter of the clarinet give the device an acoustical behavior approximating that of a cylindrical stopped pipe. Recorders use a tapered inner bore to overblow at the octave when the thumb/sign in hole is pinched open, while the clarinet, with its cylindrical bore, overblows at the twelfth. Adjusting the attitude of the bore taper controls the frequencies of the overblown notes harmonics. Changing the mouthpiece's tip opening and the length of the reed adjustments facets of the harmonic timbre or voice of the clarinet as a result of this adjustments the speed of reed vibrations. Generally, the goal of the clarinetist when producing a valid is to make as much of the reed vibrate as feasible, making the sound fuller, warmer, and probably louder. The lip position and force, shaping of the vocal tract, selection of reed and mouthpiece, amount of air force created, and evenness of the airflow account for many of the clarinetist's ability to manage the tone of a clarinet. A highly experienced clarinetist will supply the perfect lip and air pressure for every frequency note being produced. They may have an embouchure which places a good pressure across the reed by cautiously controlling their lip muscle tissue. The airflow will even be cautiously controlled by using the strong stomach muscle tissue as opposed to the weaker and erratic chest muscle tissue and they will use the diaphragm to oppose the stomach muscle mass to achieve a tone softer than a forte in preference to weakening the abdomen muscle anxiety to lower air force.