Final answer:
In a solo concerto, the form where the exposition repeats and themes are played by the soloist is called a cadenza, which showcases the soloist's skills without orchestral accompaniment.
Step-by-step explanation:
In a solo concerto, the form where the exposition repeats and the themes are played by the soloist instead of the orchestra is called a cadenza. Typically, a cadenza appears in the first movement of a concerto and allows the soloist to display their technical skill and interpretive abilities without orchestral accompaniment. It is a section where the written-out or improvised solo passages take center stage, often occurring near the end of the movement. However, it's important to note that the term cadenza generally refers to a free-form passage played by the soloist, while the actual repeat of the exposition with the soloist thematic domination might simply refer to the soloist's entry in the sonata-allegro form used in concertos.
During the Renaissance, the Italian secular genre of the madrigal and the resulting canon forms influenced later musical developments, but this is distinct from the use of the cadenza in the concerto form.