The bossa nova style fuses elements of Brazilian samba with cool jazz. While the samba has energetic drumming in addition to layered and syncopated rhythms, a bossa nova is much slower and more lyrical while still maintaining the syncopation. Cool jazz features include relaxed tempi, lightness of tone and instrumentation, flowing melodies and rich harmonies.
The bossa nova rhythm is the basis for this music genre. In Samba Em Prelúdio, the rhythm is not always easy to identify as the tempo and rhythm of some sections is very free, however, the bossa nova rhythm is always implied, as executed by the bass guitar at bar 19.