is more commonly known as solo jazz these days and is the vernacular form of dancing done to the jazz music of the 1920s-1950s and consisted mainly of the movements of popular dance at that time, much like hip-hop consists of many different types of dance moves today. Vernacular jazz was a street dance and as such, had no formal structure nor syllabus, and it was something that the black people learnt off the streets from watching other people dance. This form of dancing is not partnered.
Authentic Jazz is an integral part of Lindy Hop, but it can stand on its own as a dance. Many people who learn Lindy Hop pick up this form of jazz along the way as part of a complete understanding of the Lindy Hop.