Sound Recordings is further subdivided into two series: 45 rpm Singles and Albums. The 45 rpm domestic Singles were produced and distributed in the United States and are sorted by label and arranged numerically within each label by record number. The 45 rpm Singles that were produced and distributed outside the United States and are arranged alphabetically by country then alphabetically by label within each country then numerically within each label by record number. The Albums are arranged alphabetically by artist or band name then alphabetically by title within each artist.