The musical style evolved from samba but is more complex harmonically and less percussive. Additionally, Bossa Nova emerged primarily from the upscale beachside neighborhoods of Rio De Janeiro vs. Samba's origins in favelas of Rio. Certain similar elements were already evident, even influencing Western classical music like Gershwin's Cuban Overture which has the characteristic 'Latin' clave rhythm. The influence on bossa nova of jazz styles such as cool jazz is often debated by historians and fans, but a similar "cool sensibility" is apparent. Bossa nova was developed in Brazil in 1956 by João Gilberto. Bossa nova is most commonly performed on the nylon-string classical guitar, played with the fingers rather than with a pick. Its purest form could be considered unaccompanied guitar with vocals, as exemplified by João Gilberto. Even in larger jazz-like arrangements for groups, there is almost always a guitar that plays the underlying rhythm. Gilberto basically took one of the several rhythmic layers from a samba ensemble (specifically, the tamborim) and applied it to the picking hand.Bossa nova is at its core a rhythm based on samba. Samba combines the rhythmic patterns and feel originating in former African slave communities. Samba's emphasis on the second beat carries through to bossa nova (to the degree that it is often notated in 2/4 time). When played on the guitar, in a simple one-bar pattern the thumb plays the bass notes on 1 and 2, while the fingers pluck the chords in unison on the two eighth notes of beat one, followed by the second sixteenth note of beat two. Two-measure patterns usually contain a syncopation into the second measure. Overall, the rhythm has a swaying feel rather than the swinging feel of jazz. As bossa nova composer Carlos Lyra describes it in his song "Influência do Jazz", the samba rhythm moves "side to side" while jazz moves "front to back".