"If you can count to three, you can samba," says our (beautiful, graceful, Brazilian) dance teacher Sabrina, brightly. It's the second day of a two-week holiday and I am standing in the Aulas Marinho Braz, the coolest dance academy in Rio, in the sophisticated neighbourhood of Largo do Machado.
There are seven of us in the group, three men and four women, and we are here to master the sensual and frenetic art of the samba. In just 18 hours. And if that isn't ambitious enough, at the end of the fortnight we will join up with one of the city's top samba schools to demonstrate our prowess in a grand finale to beat all finales - the Rio Carnival. No pressure, then.
The idea for the holiday was hatched by two British women, Teresa Keohane, 35, and Kate Nowakowski, 29, who met in Rio last year where Teresa was working as a volunteer in a social project, Kate as a music writer.
They noticed that many visitors found it hard to get beyond the typical tourist experience, so decided to share their knowledge of the city while giving something back to its most deprived inhabitants. Jingando Holidays - the Portuguese name roughly translates as X Factor - was born.
The holidays combine dance lessons, tours of the city's nightlife and language lessons with one day of voluntary work. The reward, at the end of it all, is the chance to participate in the greatest party on earth.
On the first day, we visit the small favela of Julio Otoni. Part of the price of the holiday goes towards helping to run an after-school club here, which plays a vital role in keeping the children away from criminal gangs in the favelas.
In the club, children chat, paint pictures and leap about, but Teresa says they took a while to get used to its structure. "Their behaviour has improved and they are much more engaged than when they first attended," she says.
A project is also under way to give the entire hillside of houses a new lick of paint. People from the outside will see brightly coloured buildings rather than a decaying slum. People on the inside will feel increased pride in their homes. As I help paint a house a vivid turquoise, a young boy with a gun leans nonchalantly against the wall.
Our ladder won't reach the top of the house, so we ask the owner, a 50-something woman, if we can come in and hang out of one of the upstairs windows to finish the job. She lets me into her home and I struggle on while a gaggle of people gather to watch. She and her daughter laugh at me teetering on the window ledge, then point at a comedian on television doing a silly dance in a carnival wig. I think they're making a connection.
As the week goes on, we slowly master the samba. All too soon, it's my turn to do some dancing in the carnival. The official parades run for three nights in the specially constructed Sambadrome on the city's outskirts.
The first night is a special children's parade and our job is to herd them along as they parade down the 700m runway through the middle of the Sambadrome. I am allocated a group from the Prazeres favela.
Their excitement is at fever pitch as they gather around me shouting in Portuguese. They are unimpressed when they discover I can't speak the language. This is a bit unnerving but, despite the setback, we manage to find common ground. We count to 10 in English and then Portuguese. Then they all shout: "Te amo [I love you]."
The next night, in full costume, the other visitors and I take the subway back to the Sambadrome.
All the samba schools - dance clubs from each area of the city - pick a different theme, ranging from historical to abstract. One school depicts the history of photography, another the Pan-American games - with dancers dressed as tennis balls.
We are to dance with the Tijuca school and my costume is based on Oxala, a male god of procreation and harvest. It consists of a white and silver crown, a white dress with a hooped skirt and a dove (not live) on a wooden stick that I shake in the air until it flaps.
We stop in a side street to put the hoops in our skirts and spot hundreds of costumes and floats sailing past, including a Buddhism-themed float - all vibrant red and gold - then a surreal merry-go-round of giant zebras. All around us are dancing fishes, bees, aliens and antelopes.
The heat is stifling. We queue for at least an hour before we can even set foot on the Sambadrome runway. The organiser, exasperated in the heat, screams: "Rows of seven." Someone has lost their crown, someone else needs the loo, two people have accidentally locked shoulder pads and have to be prised apart. Then we're off. Phillipe, our leader, leaps around like a deranged jester.
We are stationed behind a float pushed by a team of dressed in the emerald green of the Tijuca school. They cavort wildly and wave to the crowds, all while pushing the heavy float. We dance behind, wiggling our hips and shaking our birds. Soon inhibitions are shed and we start to samba, sweat pouring off us as we try to keep in line.
The music blares, the crowd roars and we blend into the costumed plumage around us. We may just be tourists, but for the next 80 minutes, we are absorbed into the sparkling, samba-ing heart of the world's greatest party.
You can find out more about Jingando Holidays at www.jingandoholidays.com.
* Rachel Foster travelled to Rio de Janeiro with Jingando Holidays.