Montgomery County Agricultural Fair Basic event infoEvent date: 08/17/2024 - 2:00pm to 7:00pmLocation: Montgomery County Fairgrounds Gaithersburg , MD United States See map: Google Maps Maryland US Public event fieldsLook for Harmony Express barbershop singers strolling throughout the Upper Fairgrounds. If you enjoy singing, ask to join in singing a tag! We love to share the barbershop sound.