American Sheet Music: ca. 1820-1860

Building the Digital Collection

The materials in Music for the Nation: ca. 1820-1860 were scanned from seventy-nine reels of 35mm microfilm produced by the Library of Congress Photoduplication Service to preserve the originals in the Library's Music Division. Representing the years 1820-60, the collection includes approximately 80,000 images or 15,448 items. The duplicate or "scanning" negative was printed directly from the master microfilm held by the Photoduplication Service and was processed to maximize the quality of the resulting digital images. All microfilm scanning was performed by Preservation Resources in Bethlehem, Pennsylvania.

Typically, an item of sheet music is four pages long with a front and back cover. On microfilm, sheet music appears as 2A position (cine) frames, split for single-image presentation as digital images. Most of the sheet music material was scanned as bitonal TIFF (Tagged Image File Format) images at 600 dpi with Group IV compression. Since many of the covers exhibited tonality, they were scanned as 200 dpi grayscale JPEG File Interchange Format (JFIF) images, as were any images in which the originals appeared soiled, damaged, or deteriorated on the microfilm (these were compressed at quality factor 20). The grayscale solution was also used for other problem pages or frames. As with handwritten manuscript materials, the tonal capture suppressed some of the print-through in the covers so that the text is readable. Similarly, stamps and markings on the covers were enhanced and made legible by grayscale capture. GIF images were created for all the sheet music items to enable efficient download through the American Memory page-turner feature.


American Sheet Music: ca. 1820-1860