The term "mainstream" was coined by jazz authority Stanley
Dance in the 1950s in an effort to describe what was at that time the work of
contemporary musicians who discovered the foundation for their inspiration and
efforts in the music and approach of the swing era as it was developed in the 1930s and
1940s. It was meant to differentiate their work from the newly emerging schools
of modern jazz, such as bebop. Labels like "big band music" and "swing" had already
managed to attract a nostalgic glow about them, lessening their usefulness in
describing the relevance of more recent recordings. The boundaries encompassed
by the term "mainstream jazz" have gradually broadened over the years (today some
elements of bebop and post-bop, for example, are widely considered mainstream) and today it
is employed more liberally, although such esoteric developments as the avant-garde
and fusion styles would still be considered to lie outside its scope.