John L. Kelly, Jr.

John Larry Kelly Jr. was born in Corsicana, Texas, in 1923. He served as a naval aviator during the Second World War before studying physics at the University of Texas at Austin, where he earned his doctorate in 1953 with a dissertation on the elastic properties of materials. He first worked in the oil industry as a research physicist before joining Bell Laboratories in Murray Hill, New Jersey. There he became a staff scientist in the Acoustics and Information Theory departments, conducting research on data transmission, communication theory, and speech synthesis. By the early 1960s he was head of Bell Labs’ Information Coding and Programming Department.

Kelly’s research at Bell Labs reflected a range of interests, from the mathematics of information to the mechanics of the human voice. Working within Claude Shannon’s Information Theory group, he sought to understand how probability and feedback could describe systems of communication and control. His 1956 study A New Interpretation of Information Rate proposed a model for using information to optimize gain, work that became known as the Kelly criterion and later influenced economics, finance, and computing. As head of the Information Coding and Programming Department, Kelly also investigated the synthesis of speech, viewing language and sound as parallel forms of information processing. In 1961 he collaborated with Carol Lochbaum, Louis J. Gerstman, and Max Mathews to program an IBM 7094 computer that recited lines from Hamlet and sang Daisy Bell (Bicycle Built for Two) at a meeting of the Acoustical Society of America. The performance marked a turning point in the history of computer speech and music and became one of Bell Labs’ most celebrated demonstrations.

The 1961 demonstration of computer speech at Bell Labs soon became a landmark in science and popular culture. Guinness World Records credited the Daisy Bell recording as the first song ever performed by a computer, and its mechanical voice inspired the unforgettable HAL 9000 sequence in 2001: A Space Odyssey. Leading the Information Coding and Programming Department, he was regarded by colleagues as one of Bell Labs’ most imaginative and influential scientists. Kelly passed away in 1965.