Around 1976, Hartman began using one of the rooms of a colonial home in Westport, Connecticut (dubbed “The Schoolhouse”) to serve as a recording studio. The rest of the house's rooms were wired for recording and to allow for different sounds by the artists. He produced albums for artists such as .38 Special, Foghat, David Johansen and Rick Derringer. During late 1977, blues legend Muddy Waters used "The Schoolhouse" to record his album "I'm Ready". Hartman ran the recording board for the sessions and Johnny Winter served as the producer.