10. The Numerical and Enigmatic Canons, which, like everything that partakes of the nature of a riddle, are more easy to invent than to solve, and seldom yield the smallest compensation for the time and trouble bestowed on them. In former times people took a pride in racking their brains with such contrivances; the world is however grown wiser![28]
The Canon in the unison, for similar voices, is, properly speaking, nothing else than a complete duet, trio, quartet, &c., in which the parts come in one after the other, each commencing when the preceding one has finished the melody. The voice, or part, beginning second, is usually that which forms the base, and, conjoined with one or two parts, completes the whole. Example. [To which we have applied a stanza from Otway’s Enchantment.]
Plan of a terminating Canon in unison, for Three Treble Voices.
In the following manner it becomes a Close Canon, and the third part is written next after the first.[29][30]
In such alternation of the voices, the whole may be repeated as often as the singers please, or till the hearers are tired. As each must sing the whole quite through, the compass of the notes is to be well considered, so that no one lies too high or too low. As an Open Canon, this composition presents itself in the following form.