Chapter 1: A Great and Secret Power
SPOTIFY PLAYLIST
Recordings of some of the patriotic or war-related songs popular with soldiers (Union and Confederate).
Bugle Calls AND DRUM BEATS of the Civil War
The Civil War occurred before the invention of sound recording, but many of the songs and sounds from that era have been recorded subsequently. Numerous drum beats and bugle calls are available on YouTube:
The manual from which the drum beats were taken is available here (drum beats appear on pp. 227-72): https://archive.org/details/infantrytacticsf01brig/page/n5/mode/2up
Spotify, it should be noted, has numerous albums of music from the Civil War era, including The Civil War: Its Music and Its Sounds; Home, Sweet Home: A Civil War Sampler; and multiple recordings by a group of Civil War re-enactors, the Second South Carolina String Band.