At the same time that big bands were dominating the music scene in the 1930s, small groups were “quietly” creating some of the most innovative jazz of the decade. Unlike the swing bands that slowly became larger, played louder, reached for higher notes (especially the trumpet sections but also some of the saxophonists), and featured vocalists more and more prominently, the small groups tended toward subdued performances, concentrated on individual and often more extended improvisation, and, if they included a vocalist such as Mildred Bailey or Billie Holiday or even Fats Waller, emphasized jazz singing rather than pop crooning. Even though the small-group sides were not million-selling hits or anything near, a number of them represented highly influential recordings that would profoundly affect the future of jazz.
Some of the musicians who made such important small-group recordings were also well known for their work with the big bands, but it was often only through sessions with groups smaller than ten members that such figures as Coleman Hawkins, Benny Carter, Lester Young, Lionel Hampton, Benny Goodman, Artie Shaw, Bud Freeman, Jack Teagarden, Bunny Berigan, Harry James, Charlie Christian, Roy Eldridge, Teddy Wilson, and many others were able to reveal and develop their talents free of the limitations of a big-band format. In the mid to late ’20s, Louis Armstrong had established his reputation through his small-group recordings, but during the ’30s he mainly presented himself in the context of larger ensembles. However, other important soloists, especially those developing the vital role of the saxophone in jazz, carried on Armstrong’s small-group initiative and contributed significantly to the ongoing creation of the music’s artistry. As the big bands slowly drifted toward enervation, the small groups often grew more innovative with regard to their importance as training grounds for the next generation of jazzmen who would extend swing into bebop and beyond.
One extremely significant aspect of the small-group session was that it