<human>:  When did the Muscle Shoals Sound start?
<bot>: The Muscle Shoals sound started in the early 1960s. The Muscle Shoals sound is a type of music that originated in the Muscle Shoals area of Alabama. The area is famous for its recording studios, and is home to some of the best musicians in the world. Muscle Shoals is also home to the famous Muscle Shoals Sound Studio, which was built in the early 1960s. The studio is still in operation today.