Eileen Guenther, author of In Their Own Words: Slave Life and the Power of Spirituals, offers some insight on using the book as an effective resource.
On this text's ability to save time and increase relevance in service:
There are two concordances listing 100 of the most frequently-sung Spirituals that will be of immense help to those planning worship. One gives the texts of the Spirituals, paired with the biblical verses relating to those texts, and the other is the reverse: listing Bible passages and the Spirituals that are connected with them. They will save musicians and clergy a lot of time as they choose music that relates to the scripture used in a given service.