In the exposition, a short motif is introduced by one voice in the tonic key.
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At the end, the music will usually return to the tonic key in preparation of the recapitulation.
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The first subject group need not be entirely in the tonic key.
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The movement does not conclude in its tonic key, but instead reaches a final cadenza that leads directly to the finale.
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The first section is a complete musical entity, ending in the tonic key, and could in principle be sung alone.
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The movement ends in its tonic key, G major.
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In particular, the exposition and coda tend to emphasize the tonic key, whereas the episodes usually explore more distant tonalities.
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The subject is then repeated in the second voice in the tonic key while the initial voice either plays a countersubject or plays in free counterpoint.
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The introduction also employs the use of the mediant to tonic relationship which further distorts the tonic key until it is finally played by the bassoon in the lowest possible register.