The Trumpet

The modern trumpet has three valves and a bore that is partly cylindrical, partly conical. The standard orchestral trumpet, built in B-flat, has a range of about three octaves extending upward from the F-sharp be extending upward from the F-sharp below middle C(F3 sharp = 185 Hz). Models in D, C, and other pitches also exist. 现代小号有三个阀门，其管身部分为圆柱形，部分为圆锥形。标准的B小号小号的音域约为三个八度，从F小号音域向上延伸，F小号音域位于中央C以下（F3 sharp = 185 Hz）。也存在D、C及其他音高的型号。

Music for all models is written as if they were C trumpets (written C sounds B-flat for a B-flat trumpet). This allows players to switch instruments without learning new fingerings.

The cornet is very similar to the trumpet except that it has a conical bore throughout its length while most of the trumpet's bore is cylindrical. Another relative of the trumpet is the flugelhorn , sometimes dubbed the "valved bugle" . It has a mellower sound than the trumpet.

Valves for Trumpet and Horn

The three valves of the trumpet add lengths of tubing to the instrument to lower the pitch. The first valve lowers it by a whole tone, the second by a semitone, and the third by a minor third. 小号的三个阀门向乐器添加管段以降低音调。第一个阀门降低音调一个大二度，第二个降低一个半音，第三个降低一个小三度。 Based on a length of 148 cm, valve 1 would have to add 17.9cm, valve 2 8.6 cm, and valve 3 would need to add 27.8 cm. Note that valves 1 and 2 depressed together lengthen the tube by 26.5 cm and are not equivalent to a minor third. 基于长度为148厘米，阀1需要增加17.9厘米，阀2需要增加8.6厘米，阀3需要增加27.8厘米。注意，阀1和阀2同时按下会使管子延长26.5厘米，它们并不等同于一个小三度。

When a trumpet valve is up, the air goes straight through, and when it is depressed, a different air path is opened which adds a section of tubing. The length to add for the three valve intervals is calculated by using the fact that the frequency of an air column is inversely proportional to length.

Horns may use rotary valves. The version at left is patterned after a sketch in Wolfe. 喇叭可能使用旋转阀。左边的版本是根据Wolfe的草图设计的。

Trumpet Resonance Curve

A trumpet exhibits natural resonant frequencies which follow a harmonic sequence fairly closely up to the tenth harmonic. This harmonic sequence is obtained with the help of the bell effect and the mouthpiece effect on the resonances. A unique pedal tone can be played in addition to the resonant frequencies.

While the pedal tone of the trumpet can be demonstrated, it is much harder to play than with the trombone and other bass brass instruments and is not considered to be as useful, musically.

Trumpet Resonance Data

The data for the trumpet resonance curve reported by Backus were obtained by what he calls the capillary excitation method. The air column is excited by a loudspeaker type driver through a capillary tube into the air column near the mouthpiece end. The mouthpiece is closed off by a response microphone which measures the resulting mouthpiece pressure in response to the excitation. Note that the resonant peaks increase until about the 7th harmonic. This increase is attributed to approaching the helmholtz resonant frequency of the mouthpiece.

Above that peak, the amplitude diminishes rapidly. Backus attributes this to the fact that the wavelength of the 10th harmonic at about 1170 Hz is about equal to the circumference of the bell. Above that frequency, most of the wave energy is radiated rather than being reflected to contribute to the standing waves necessary for resonance. 在此峰值之上，振幅迅速减小。Backus认为这是因为第10泛音的波长约为1170 Hz，大约等于钟的周长。在此频率以上，大部分波的能量被辐射出去，而不是被反射以贡献给维持共振所需的驻波。 Backus报告的喇叭共振曲线数据是通过他称为毛细激发法获得的。通过毛细管将声音激发到喇叭管靠近喇叭口的一端，由扬声器类型驱动器激发空气柱。喇叭口被一个响应麦克风封闭，该麦克风测量激发后喇叭口处的压力。请注意，共振峰直到大约第七次谐波时才增加。这种增加归因于接近喇叭口的亥姆霍兹共振频率。