Since 1976, Joe Blumenthal has owned and operated Downtown Sounds in Northampton, one of the most well-known music shops in the Pioneer Valley, and now the iconic music shop is transitioning to become a worker-owned cooperative once Blumenthal, 70, retires. Whether you’re looking for music lessons, a high-end Rickenbacker electric guitar, repairs, or a banjo, odds are Downtown Sounds has what you need.