To understand what we hear from recordings we must first understand them as sources of evidence. Although initially the usefulness of recording was unclear, in the twentieth century the industry became profitable through focusing on entertainment. Providing consumers were entertained they were content not to enquire too closely into the distortions and illusions that recording created, especially as sound quality improved and relative prices decreased. Thus throughout the past 110 years records have been widely if naively accepted as surrogate accounts of live performance. Nevertheless, reading through the medium reveals the extent to which recording transmutes music-making. Even when production and record seem at one, as in much rock music from the 1960s when albums were created over long periods in the studio, records contain secrets that challenge preconceptions. Outlining the most significant is one purpose of this chapter. First, though, we need to know how to find recordings, and how to date and place them: then we shall be in a better position to ask about the sounds they encode.

Discographies and information trails

There are many discographies and other useful materials available via the internet, but it is often impossible to estimate how accurate the information is for there is less obvious editorial control or review than in printed publications. Nevertheless, a comprehensive online discography for a single performer, Eugene Ormandy for example, is often reliable, and when an institution like the London Symphony Orchestra puts up discographical information one has good reason to trust it. Digging into the frustratingly awkward catalogues of the great sound archives, such as those at the British Library, Library of Congress and Bibliothèque nationale, can often yield useful information, but each is riddled with quirks and uncertainties.