What is true about a scale (Music)

The art of the monogamy period was characterized by style

Nstrumental music that supports the main part(s) chamber music 2. a large group of instruments usually including woodwinds, brass, and percussion band 3. music written for small ensembles for an intimate setting accompaniment 4. a person who leads an ensemble conductor 5. an electronic keyboard capable of multiple instrument sounds

The opening section sounds marchlike, with accented beats and alternations between instrumental groups. eventually, a total change of character marks a short, new section. at approximately which time interval from the beginning does this appear?