The Big Band ERA was a period of time in the 1930s and 1940s when large jazz ensembles, known as big bands, were popular. These bands typically consisted of 10 to 25 musicians playing a variety of instruments, including saxophones, trumpets, trombones, and drums. The Big Band ERA was characterized by its swing music, which was a style of jazz that emphasized improvisation and syncopation. The ERA saw the emergence of some of the most influential jazz musicians of all time, such as Duke Ellington, Count Basie, and Benny Goodman.