If you wanted to cite a music CD in Chicago, you would use the following format:
Name of Group/Performer/Composer, “Title of Song,” recorded date (if known), Title of Album, Label, year of release, medium.
"Abolitionist hymn" is a song performed by Hermes Nye on the CD Ballads of the Civil War, 1831-1865. It was published in Washington D.C. by Smithsonian Folkways Recordings in 2006.
Using this information, the Chicago citation would be:
Nye, Hermes, “Abolitionist hymn,” Ballads of the Civil War, 1831-1865, Smithsonian Folkways Recording, 2006, CD.
If you wanted to cite an audio recording found online using Chicago, you would use the following format:
Last name, First name Middle initial. Title of Work. Format. (City: Publishing Company, copyright date. Source, Collection. Medium, http://...(accessed date).
If you listened to StoryCorps's "New Orleans Pump Station workers Rufus Burkhalter and Bobby Brown remember the night Hurricane Katrina hit" at http://storycorps.org/listen/rufus-burkhalter-and-bobby-brown/ on January 1, 2013, the citation would appear as follows:
Brown, Bobby and Rufus Burkhalter, “New Orleans Pump Station workers Rufus Burkhalter and Bobby Brown remember the night Hurricane Katrina hit.” MP3. Brooklyn, NY: Story Corps, 25 August 2006. http://storycorps.org/listen/rufus-burkhalter-and-bobby-brown/. (01/01/2013).