Final answer:
The harmony in Bach's Orchestral Suite No. 3 Gigue is characterized by a polyphonic texture and functional progressions, common to Baroque music, providing a dynamic and dance-like quality.
Step-by-step explanation:
The harmony in the opening of the Gigue from Bach's Orchestral Suite No. 3 exhibits a rich and polyphonic texture that is characteristic of Baroque music. The harmonies are generally built on functional progressions that adhere to the principles of tension and resolution, creating a dynamic and elaborate musical fabric. In typical Baroque fashion, the harmony may often feature complex counterpoint, with multiple lines of music moving independently yet harmoniously. There's a sense of drive and momentum in the harmony of a Gigue, emphasizing a joyful and dance-like quality inherent to this movement of the Suite.