Final answer:
The phrase 'national chest' refers to America's collective cultural and musical heritage, including both singing abilities and use of homemade musical instruments in folk music traditions.
Step-by-step explanation:
The phrase "national chest" found within the context of American folk music and the historic use of the term broadly refers to the collective cultural and musical heritage of a nation—in this instance, America. It signifies the repository of songs, styles, and instruments that comprise the folk music tradition in the United States.
This concept encompasses not only the singing abilities of Americans across the nation but also the use of homemade instruments in folk music. These instruments were often simple and portable, such as harmonicas, violins, guitars, and banjos, which were popular because they could be easily carried and did not require elaborate setups.
In the folk traditions, it was common for musicians to either build their own musical instruments from available materials or use available household items in a creative way.