Which instruments were included in dance bands of the 1930s and 1940s?

During the 1930s and 1940s, dance bands—often referred to as big bands—typically organized their instrumentation into three primary sections: brass, woodwinds, and rhythm. These ensembles generally consisted of 12 to 16 players.1

The rhythm section underwent a notable evolution during this period. Earlier jazz instruments, such as wind basses and banjos, were largely replaced by stringed basses and guitars, which helped create a lighter, more fluid sound suited to the 4/4 meter that became standard for swing music.1

The bands utilized these sections to create a "call-and-response" style, where different choirs of the orchestra were played off against one another or against individual soloists. While these large orchestras were the hallmark of the era, the period also saw the emergence of smaller "combos" extracted from larger bands, which featured varied instrumentation including piano, vibraphone, trumpet, saxophone, and bass.123