Those are called big bands. These were popular in the 20s and up to the maybe 60s. It became cost prohibitive for a club to pay an entire 10-20 person band. P

Those are called big bands. These were popular in the 20s and up to the maybe 60s. It became cost prohibitive for a club to pay an entire 10-20 person band. Plus improving speaker & playback technology made it possible for smaller bands & DJs to provide the music.