Bossa nova is a relaxed style of samba developed in the late 1950s and early 1960s in Rio de Janeiro, Brazil. It is mainly characterized by a calm syncopated rhythm with chords and fingerstyle mimicking the beat of a samba groove, as if it was a simplification and stylization on the guitar of the rhythm produced by a samba school band. Another defining characteristic of the style is the use of unconventional chords in some cases with complex progressions and "ambiguous" harmonies. A common misconception is that these complex chords and harmonies were derived from jazz, but samba guitar players have been using similar arrangement structures since the early 1920s, indicating a case of parallel evolution of styles rather than a simple transference from jazz to bossa nova. Nevertheless, bossa nova was influenced by jazz, both in the harmonies used and also by the instrumentation of songs, and today many bossa nova songs are considered jazz standards. The popularity of bossa nova has helped to renew samba and contributed to the modernization of Brazilian music in general.