a device of thematic development belonging to polyphonic music of all types, whereby a voice or part repeats a figure of melody previously heard in another voice or part. Imitation may be held to include every form of Canon (q.v.) together with such recognised classical formulae as the subject and answer of a fugal exposition and stretto. (See F u g u e and I n v e b t ib l e Co u n t e r po in t .) I t , however, covers more ground than any of these processes or all of them taken together. In modern music it does not necessarily entail any literal copying of the first statement. In the classical period of the sonata imitation was used freely, most frequently by preserving the rhythm and the general outline (rise and fall) of the melodic figure, while altering the intervals. . 1st Vln. 2nd Vln. Qnintet in G minor.-M o z a r t . In this and countless parallel cases the melodic intervals of the figure are altered in conformity with the harmonic plan. But a new phase of imitation is to be noted in certain more recent works, where the imitations, so far from being modified in this direction, are deliberately arranged to avoid compliance with any harmonic scheme. Here are two groups of imitation, (a) and (b), so designed that the tonality of each part conflicts with those about it. The passage is one of ironic humour, but it is typical of a style Clar. Eb. Clar. Bb. O b . I. * Heldenleben.' -S t r a u s s . Flute. followed by many later composers without any humorous intention. Theorists have used such expressions as ' polytonality ' and * atonality * to describe it. (See H armony.) The noteworthy point here is that in such passages as this the imitative nature of the melody affords a principle of coherence which serves to mitigate the most extreme harmonic conflicts. (Cf. F orm.) c .