Table III., showing orchestral pitches obtained in 1899, for the measurements of which the writer is responsible, prove how chimerical it is to hope for greater accuracy than is found between 435 and 440 vibrations a second for a', inasmuch as temperature must always be reckoned with.
The narrower term "orchestration" is applied to the instrumentation of orchestral music. Since the most obvious differences of timbre are in those of various instruments, the art which blends and contrasts timbre is most easily discussed as the treatment of instruments; but we must use this term with philosophic breadth and allow it to include voices.
Modern composers have often produced their most characteristic orchestral effects with fewer contrasting elements than Bach uses in his Trauer-Ode, in the pastoral symphony in his Christmas Oratorio, in the first chorus of the cantata Liebster Gott, wann werd' ich sterben, and in many other cases; but the modern instrumental effects are as far outside Bach's scope as a long passage of preparation on the dominant leading to the return of a first subject is beyond the scope of a gigue in a suite.
It is in the attempt to supply the place of this continuo (or _ figured bass) by definite orchestral parts that modern per formances, until the most recent times, have shown so radical an incapacity to grasp the nature of 18th-century instrumentation.
For example, it has often been said that the extent to which their orchestral viola parts double the basses is due, partly to bad traditions of Italian opera, and partly to the fact that viola players were, more often than not, simply persons who had failed to play the violin.