Final answer:
During the Swing Era, the rhythm section in jazz bands changed to include a piano, guitar, bass, and drums. This change resulted in a fuller and more dynamic sound.
Step-by-step explanation:
In the Swing Era, the rhythm section underwent significant changes. Traditional jazz bands typically had a rhythm section consisting of a piano, banjo, and tuba or bass. However, during the Swing Era, the rhythm section evolved to include a piano, guitar, bass, and drums. The addition of the guitar brought in a new harmonic element, and the drums became more prominent, providing a stronger and more driving rhythm. This change in instrumentation led to a fuller and more dynamic sound, which was a hallmark of the Swing Era.