Book excerpt: This easy-to-use dating guide for 93,000 individual 45 and 78 rpm records released by almost 2,500 United States record companies enables the reader to date the specific month a record was released. Record companies are listed in alphabetical order; subsidiary and related companies are also arranged alphabetically following the parent company with cross-references from the name of the subsidiary. Under headings for each label, columns of record release numbers and release dates indicate the month and year a record was formally available to the public, based upon when notification was published in the trade journals, periodicals, and related sources. This book presents information for numerous companies for which no comparable listings previously existed. In addition to aiding record dating, the guide sheds new light on the history of specific recording companies and provides additional information for the history of the recording industry as a whole.