This collection contains photocopies of music scores and sheet music composed by Alfred Harding Yopp, a Wilmington musician and businessman. Yopp's music is largely religious in nature, and additional music not written by Yopp is also included. Collection material also includes newspaper clippings, programs, and correspondence related to Yopp's music, eduction, and career.

This collection is composed of undated piano and choral sheet music consisting of music from play productions and operas, official United States military songs, and other songs of the era. Well-known pieces such as People Will Say We Are In Love from the musical Oklahoma and the musical score from Gone With The Wind are contained within this sheet music collection. The only dated source, The Marine's Hymn, is from 1942 and is the oldest and official song of the United State Marine Corps.