Page:Essentials in Conducting.djvu/61

Rh gives sixty-four clicks per minute; when set at 84, or 112, corresponding numbers of clicks per minute result; so that in this way the composer is able to indicate precisely the rate of speed of his composition by indicating the number of beats per minute. The indication = 84 means that the sliding weight is to be set at the point marked 84, the metronome then clicking eighty-four times per minute, each of these clicks indicating a quarter-note. But if the marking is = 64, this means that sixty-four half-notes are to be performed in a minute, a tempo equal to one hundred and twenty-eight quarter-notes in the same composition. In compound measures such as 6–8, 9–8, et cetera, the tempo indication shows the number of eighth-notes per minute if the composition is in slow tempo; but in moderate and rapid tempos the direction is usually given by taking the dotted-quarter-note as the beat unit, thus: = 84. It is of course obvious that in this case the composer is thinking of each measure as having only two or three beats instead of six or nine.

Many instrumental compositions (particularly the older ones) are not provided by the composer with definite tempo directions; and in this case the Italian tempo terms usually give at least a clue to what the composer has in mind. These terms do not of course give us the precise tempo, but by indicating the mood of a composition they at least help one to determine the rate of speed (adagio—at ease; allegro—cheerful; largo—large, broad; andante—going; et cetera). A comprehensive knowledge of these terms from the twofold standpoint of definition and derivation is indispensable to the conductor. The most common of them are therefore defined at this point. They are given in groups in order that the student may note how much the various terms overlap in meaning.