Superseded by television as the primary source of entertainment and information, radio still has a unique place in the mass media spectrum. At once powerfully pervasive and totally invisible, it's a fascinating subject for study. On Air adopts a wide-ranging theoretical and critical approachto provide an in-depth examination of radio's codes (speech, music, noise, and silence), the conventions of using these codes, and the dominant modes of reception. The text offers a vocabulary and methodology for analyzing radio programs, drawing on work by both media theorists and professionalbroadcasters in Britain, Australia, and North America. Written by an academic and a practitioner, On Air provides a critical overview of radio for media students, as well as suggestions for practical activities, a time-line of major events in the history of radio, and a glossary of key terms.