The classification schedule for music (class M) contains call numbers for songs about specific topics. The number M1659.5, for example, followed by the first letter of the subject’s last name, represents songs about prominent or notorious people. Songs about Amelia Earhart carry the call number M1659.5.E. Songs about political parties and movements also have their own call numbers. Woman's suffrage songs are located under M1664.W8 (collections) and M1665.W8 (separate works). Patriotic societies and organizations have distinctive song numbers and include such groups as the Daughters of the American Revolution (M1676.D3), Daughters of Union Veterans of the Civil War (M1676.D4), Gold Star Mothers (M1676.G6), United Daughters of the Confederacy (M1676 .U7), and the Ladies' Auxiliary (M1676.V42). The classes M1977-M1978 represent songs of special character and are arranged topically. Homemakers and housewives, mothers, nurses, secretaries, and women in general are just some of the subjects included within this class. Searching these topical classes, however, should not be considered exhaustive. Songs that are topical in nature more typically receive the general number for popular songs: M1622 for songs published through 1923 and M1630.2 for songs published after 1923. Many others are filed by their copyright registration number.

Subject indexes to popular song literature are found in the list of print resources below. The following titles link to fuller bibliographic information in the Library of Congress Online Catalog. Links to additional online content are included when available.

For a brief historical survey of what songs were popular in a given year, see:

There are several large digital collections of sheet music that offer keyword title searching and browsing of thumbnail cover images.  Together they cover most of the nineteenth century and the early twentieth century up to roughly 1920.