But the orchestra excels even the pipe organ in the variety of beauty of its tonal coloring and in the amazing wealth of its musical effects. The orchestra conductor can "pull stops" on the orchestra that are the envy of the organist and the despair of the organ builder.



In the lower regions he can call out the ominous thunder of the tympani, the sonorous boom of the tuba, the Plutonic mumble of the bassoon, the dark, muffled zoom of the string bass, or the sepulchral moaning of the bass clarinet.

To carry the melody or tell the story of the composition, the conductor can call upon the versatile virtuoso violin, the coloratura-soprano flute, the lyric-soprano oboe, the dramatic-soprano clarinet or the martial trumpet and piccolo.

For middle voices he can choose the tenor trombone or viola, the English horn or alto clarinet, the French horn or cello. To beat a rhythm or set a tempo or punctuate a phrase, the conductor may choose among the many varieties of drums and bells and chimes, or call upon the strings to play pizzicato or the trumpets to play staccato.

The high harmonics of the strings can picture the ethereal realms of heaven, or the brass and the battery can blast the ^hearing with the echoes of hell. The flutes and oboes can paint a Corot scene of pastoral contentment, the trumpets and trombones can fan our warring spirit to white heat, the French horns can call from Alpine peak to Alpine peak, or the bassoon can perform the antics of the clown and picture the zigzag, uncertain course of the drunkard. The clarinets can dance the swift, sgrightly folk dance, the drums and piccolo can beat the cadence of marching armies. Or the slow, measured beat of the tympani and the low, muffled swish of the string bass can pace the funeral march. There is nothing, apparently, beyond the capacity of this greatest of all musical instruments the symphony orchestra.

The symphony is composed of about a hundred instruments and has a range of about a hundred semitones. Since the sound limits of the human ear are about 125 semitones, the symphony orchestra utilizes about four fifths of the range of human hearing.

The lower threshold of hearing is usually set at sixteen vibrations per second, and while the pipe organ sometimes uses this tone, four octaves below Middle C, the lowest note used in the symphony is the Bb in the fourth octave below Middle C, sounded by the giant contrabass tuba and having twenty-nine and a fraction vibrations per second.