This program covers such problems as the production of varying degrees of loudness on harpsichords and spinets, the mechanical engineering of the modern piano, the origin of scales, and the inability of keyboard instruments to produce scales in all keys exactly in tune. Synthesizers demonstrate both the problem and its solution. The progression is from electronic organs to analogue synthesizers, from purely electronic oscillations to the addition, subtraction, multiplication, mixing, and performance of additional functions that comprise the complex sounds of music. The program also looks at digital sound and musique concrète, using the BBC Radiophonic Workshop to answer some of the questions about the partnership between science and music. (60 minutes)