Final answer:
Bach used counterpoint, motivic development, and sequence in movements 1 and 2 to build complex and richly textured melodic lines, embodying the dynamism and emotional depth typical of the Baroque period.
Step-by-step explanation:
Johann Sebastian Bach, a prominent Baroque composer, utilized various techniques to build the melodic line in movements 1 and 2 of his works. In these movements, Bach often employed counterpoint, a technique characterized by the interweaving of two or more melodic lines, which are harmonically interdependent yet independent in rhythm and contour. This method creates a complex and richly textured musical tapestry.
He also made use of the motivic development, where a short musical idea or motif is repeated and varied throughout the movement, giving rise to a cohesive and intricate melodic structure. Another technique Bach used is the sequencing of a motif, where the same musical figure is repeated starting on different pitches, creating a pattern that adds to the dynamism and progression of the melody. These methods, underpinning Bach's skillful harmonic language, contribute to the development of the melodic line in a way that is typical of the Baroque period, characterized by movement, emotion, and a high level of ornamental detail.