The Chamberlin is an electro-mechanical keyboard instrument that was a precursor to the Mellotron. It was developed and patented by Iowa, Wisconsin inventor Harry Chamberlin from 1949 to 1956, when the first model was introduced. Various models and versions of these Chamberlin music instruments exist. While most are keyboard-based instruments, there were also early drum machines produced and sold. Some of these drums patterns feature Harry Chamberlin's son Richard on them.