Revelers partied into Tuesday morning at Rio's colorful Carnival parade on the second night of the "greatest show on earth," with exquisitely decorated floats and lavishly costumed performers. The night processions at Rio's renovated Sambadrome marked the high point of the pre-Lent festival, a national holiday that has brought this racially diverse country of 191 million people to a near-standstill. In Rio, a shootout between police and a drug gang that left one person dead and four wounded in a nearby slum failed to dampen the wild enthusiasm of the capacity crowd of 72,500 at the newly renovated "temple of Samba". Singer-actress Jennifer Lopez was one of several foreign celebrities to lend their star power to the event, appearing late Sunday in skinny red jeans and a sequined top. And the samba schools' parade featured gorgeous women wearing colorful feathers and very little else, much to the delight of the crowd. With a deafening burst of fireworks, Sao Clemente was the first of six elite schools to take center stage Monday night, taking inspiration from a selection of popular Broadway musicals such as "The Phantom of the Opera" and "Cabaret". The school, known for its irreverence, displayed a reclining Statue of Liberty in bikini and sandals holding an ice cream on one float. Uniao da Ilha do Gobernador, representing Governor's Island in northern Rio, followed with a tribute to London and Rio, which will host the next two Summer Olympics in 2012 and 2016, respectively. Some of the loudest applause from the crowd went to performers representing Olympic athletes holding Brazilian and Uniao da Ilha do Gobernador flags and wearing uniforms with the inscription Rio 2016. Thirteen schools are in contention for the title of Carnival champion, to be bestowed on Wednesday based on choreography, music, dancing and creativity. Seven schools held their parades late Sunday. Several have chosen to celebrate the indigenous and African roots of Brazil's northeast, particularly the rich African heritage of Bahia state. In the early hours of Tuesday, Salgueiro, which won the title in 2009, paid a tribute to so-called Cord literature, a genre of folk novels and poems which is very popular in northeastern Brazil. Mangueira, viewed as the country's most popular samba school, followed with a colorful homage to a popular Rio Carnival band, Cacique de Ramos, which has just celebrated its 50th anniversary. The school has many national and foreign star followers, including Argentine football great Diego Maradona. Unidos da Tijuca, which finished 2nd last year, and Grande Rio, one of the newest schools, were to round out the proceedings in the coming hours. Preparation for the Carnival parades start months in advance, as each samba school mobilizes thousands of fans who must create the various parts of the school's display. Residents of the city's favelas -- or slums -- are often members of a local samba school and are deeply involved with the performance and preparation of costumes. Seats at the open-air Sambadrome cost between $50 and several thousand dollars, depending on whether one sits on packed benches in the open or in air-conditioned VIP boxes stocked with champagne. Big-name companies invite luminaries like Lopez to their skyboxes to promote their brands. Up to five million people, including 850,000 tourists, are expected to attend the numerous street parties in Rio during the five-day Carnival, which was officially launched Friday. The festival is a big draw in other cities and towns as well, including Sao Paulo, Brazil's economic capital and Latin America's most populous city, and Salvador, the heart of the rich Afro-Brazilian culture.