Descargas (mostly instrumental jams sessions) where jazz-influenced improvisation was developed, were first known as "rumbitas" in the early 1940s. The musicians improvised with a rumba sensibility. By the 1950s the rhythmic vocabulary of the rumba quinto was the source of a great deal of rhythmically dynamic phrases and passages heard in Cuban popular music and Latin jazz. Even with today’s flashy percussion solos, where snare rudiments and other highly developed techniques are used, analysis of the prevailing accents will often reveal an underlying quinto structure.