General comments on digital reproductions of sound recordings for American Memory


The sound recordings in the American Memory collections available include early phonograph recordings of political speeches and vaudeville routines and two collections of recordings gathered in the field by folklife researchers. These recordings include songs, poems, and narratives.

Digital formats and resolutions

The Library of Congress does not yet make computer-based digital recordings for archival purposes. The recordings digitized for American Memory were first copied to specialized audio formats for archival purposes. The current practice is to make two DATs (Digital Audio Tape) and one 3/4 inch U-matic video tape for safety. Digital "service" versions are derived from a DAT tape. The Library expects to create new service versions over time, as network bandwidth to homes and schools increases and the technology on typical desktops improves.

Two qualities of service version are currently in use. WAVE RIFF (.wav) files are derived by sampling from the DAT at 16 bits, 22,500 times per second. To reach the widest possible audience, lower quality RealAudio files (aimed at 14.4 Kbits/sec modems) are generated in batches from the WAVE files (including transfer of corresponding information held in headers). Each RealAudio recording comprises two files; the .ra file contains the recording proper and the .ram (RealAudio metadata) file contains the metadata that facilitates the streaming capability.

A collection of political speeches, digitized earlier, was captured at lower sampling rates and is also available in .au format.

Descriptive records

The descriptive records available for these sound recordings vary widely in content and format. For two collections, item-level MARC records are available. In one field of the record, the combination of subfields $d and $f provides a unique identifier for the associated digital reproduction. For another collection, a non-MARC record includes an equivalent identifier. Files representing the recordings for each collection are available in a directory structure (known at the Library of Congress as an "aggregate") for which $d identifies the root. Filenames for the different digital versions of a recording are created by combining the $f value (which identifies the item) with distinguishing file extensions.

Collections of sound recordings available
for use in DLI - Phase II

The American Memory collections listed below, currently released or in an advanced state of production, include sound recordings. Technical summaries with considerable detail and links to samples are available for each collection by clicking on the title.

Collection title:     Click for technical summary


American Leaders Speak: Recordings from World War I and the 1920 Election, 1918-1920

59 speeches, item-level MARC records + text transcriptions

The American Variety Stage: Vaudeville and Popular Entertainment, 1870-1920

10-item sampler, songs and vaudeville routines, menu of brief descriptions

California Gold: Northern California Folk Music from the Thirties

~900 recordings (folk songs) from an ethnographic field collection, related documents; item-level MARC records

Voices from the Dust Bowl: The Charles L. Todd and Robert Sonkin Migrant Worker Collection, 1940-1941

416 recordings (songs, poems, narratives) from an ethnographic field collection, with related documents; item-level non-MARC descriptive records

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