How did Haydn use counterpoint in his string quartets and other late works?

In the late Classical period, Joseph Haydn increasingly integrated counterpoint into his works, reconciling it with the homophonic style and sonata form that defined his era.12

Haydn’s approach to counterpoint evolved significantly throughout his career:

• Sturm und Drang Period: During the 1770s, Haydn experienced a contrapuntal "crisis," leading to more rigorous and adventurous writing. This is evident in his Sun Quartets (1772), which feature fugues as final movements.2
• The "New Manner": In his Russian Quartets (1781), Haydn introduced a style where thematic material was shared equally among all string instruments rather than favoring a single melody instrument. This development was crucial for the maturity of the string quartet.23
• Late Works: In his final years, Haydn brilliantly combined symphonic principles with older contrapuntal forms in his late masses and oratorios, such as The Creation and The Seasons, which were inspired by his exposure to Handel’s oratorios.24

Ultimately, Haydn used counterpoint not to abandon Classical structures, but to enhance them, ensuring that combined melodic lines remained subservient to the harmonic design and phrase structures of his compositions.2