HAPPENIN’ OTSEGO for SATURDAY, SEPTEMBER 15 Celebrate The Harvest Season HARVEST FESTIVAL – 10 a.m. – 5 p.m. 2 days of music, performances, activities, workshops, meet the animals, learn about old-time trades, participate in the harvest. Entry, $12/adult. The Farmers’ Museum, Cooperstown. 607-547-1450 or visit www.farmersmuseum.org/Harvest-Festival BENEFIT JAM SESSION – 3 – 10 p.m. “Play it Forward” all day jam session with musicians from Florida, Long Island, Brooklyn mix with local musicians. All instruments, genres, vocalists invited. Enjoy raffles, BBQ, music. All…