Rio de Janeiro and in the usual "pagodes" – festive gatherings, with music, food and drink – since the first decades of the 20th century. With remote African roots, this sub-genre is characterized by a highly percussive pandeiro beat (using the palm of the hand in the center of the instrument for snapping), a greater tone harmony (usually played by a set of percussion instruments normally surdo, pandeiro and tamborim and accompanied by a cavaquinho and/or classical guitar) and the art of singing and creating improvised verses, almost always in the character of challenge or contest. This essence based on improvisation was taken to the record studios, where partido-alto became a style with more musicality and made with more concise verses and written solos, instead of improvised and spontaneous singing according to traditional canons. This stylized partido-alto was released on several collective LPs, released during the 1970s, whose titles included the subgenre's own name, such as "Bambas do Partido Alto", "A Fina Flor do Partido Alto" and "Isto Que É Partido Alto", which included samba composers such as Anézio, Aniceto, Candeia, Casquinha, Joãozinho da Pecadora, Luiz Grande and Wilson Moreira, although not all were versed in the art of improvisation. Another artist who stood out as a partideiro was Bezerra da Silva, a singer who would be noteworthy in the following decade with sambas similar to the partido-alto and themed in the world and in the underworld of Rio's favelas. The 1970s were also a time of major changes in Rio de Janeiro samba schools, and the music industry began to invest in the annual production of LPs of the sambas de enredo presented at the carnival parades. In the early years, it was common to release up to two albums, the first containing the sambas-enredo of the parades and the second with sambas depicting the history of each samba school. Beginning in 1974, the annual release began to focus on a single LP for each first and second division of Rio carnival parades Even during this period, "rodas de samba" ("samba circles") began to spread as a fever throughout Rio de Janeiro and other Brazilian cities. Originally restricted to the backyards of sambistas' residences and the samba school headquarters, these informal meetings have taken on a new meaning in clubs, theaters, steakhouses, among others, with the promotion of "rodas de samba" with stage and microphones and the participation of