What is the first part of the sonata form?

Exposition

Explanation: The parts of the sonata are, in order, Exposition, Development and Recapitulation. (there can be an introduction that would be previous to the exposition, but it is optional, so i would not consider it the first part of the sonata)

Then, the first part of the sonata is the exposition, which is where the primary themes of the sonata are presented.

explain what the look like and look at when they where created

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