While Latin dance workshops are a popular way for single people to meet prospective partners, Kassabova advises caution. "It's not always as good an idea as it seems," she laughs ruefully. "But it's perfect for meeting people. There's been a renaissance in couple dancing and social dancing precisely because a lot of people are feeling isolated. Many urbanites of my generation are not religious and have children later in life, or not at all. People are being more or less voluntarily displaced from one country to the next and sometimes feel like they're stuck between two passports. Couple dancing and especially something with a tradition like tango has hit a nerve. It's about both the past and the present and it gives you intimacy or at least the illusion of intimacy."
Taking its name from the length of a tanda - a sequence of three or four songs - Twelve Minutes Of Love touches on how tango fulfills some basic needs for human contact and interaction, even if it is only for a few minutes. "Sometimes that's enough if you're a busy city person," says Kassabova. "But even if you don't end up in a relationship through the dance, the whole social dimension of it is wonderful. You end up making friends and that's a very healthy thing, until it isn't. It can fill a very serious gap in our lives. When you're in an embrace with a stranger or a friend, a lot of boundaries and prejudices come down. It humanises you to be holding someone and moving with them to beautiful music."
Ironically, considering its enduring appeal to those on the edge of society, tango's roots are "a wunderkind of cultural mutation" that grew out of the collective experiences of the descendants of African slaves and impoverished Italian and Spanish immigrants who settled in Argentina in the mid-19th century, Kassabova says.
"It was created by outsiders, who were homesick and felt misplaced," she says. "They didn't know what else to dance so they created their own dance, their own music. Tango is really born out of crisis. Buenos Aires was a new metropolis a century ago and all these other big cities like London and Marseilles and later Auckland and Sydney were places of great unhappiness and broken dreams as well as great creativity and hope. You find all of that in tango."
Popular during the early part of the 20th century, tango went through "a long, dark age" in the 1960s and 70s before its recent resurgence. "Tango was killed by the Beatles and the military junta in Argentina, so it went underground," says Kassabova, who credits tango's newfound popularity to the late composer Astor Piazzolla. "He turned up on the scene in the 80s and revived tango single-handedly with a new style that has become known as tango nuevo."
In the past decade, French trio the Gotan Project have brought a whole new audience to the music with their tango-inspired electronica that is best summed up by their recently re-issued 2001 début album La Revancha del Tango, which translates as "'tango gets its own back".
"Their music is sometimes played at milongas," says Kassabova, referring to a tango social event. "I first heard them around about the same time that I discovered tango. I like them because I'm not a purist. I appreciate all forms of tango."
However, she is not as fond of reality shows such as New Zealand's Dancing With The Stars and Britain's Strictly Come Dancing, which favour ballroom tango. "It's like the simpleton cousin to social tango," she says.
"The revival of social dancing with programmes like that is a really good thing but there's one fundamental difference, which is why I don't go for them: they're about how people look. It's about one couple performing with glitter and disco balls whereas social tango is about how people feel when they dance, the deep experience of connecting or disconnecting from another person, how music makes you feel and how you become more yourself. It's about the communal experience as well as the couple experience."
But Kassabova believes mastering such a skill can only be beneficial. "It's a journey of self-improvement and self-learning," she says. "You learn things about yourself, even if it's through Strictly Come Dancing. My own story about tango in this book is about profound changes in people's lives. As with a good fiction story, your character will change by the end. It's about how the culture of tango has transformed me and my life; although not always in a good way, and that's also true for hundreds of thousands of other people around the world."
Along with its links to film and contemporary music, Kassabova highlights tango's literary connections, frequently quoting from and alluding to the work of the late Argentine novelist Jorge Luis Borges. "Tango is an old and rich art form so when you're writing a book about tango, it's impossible not to have literary and other cultural allusions," she says.
"Borges is the great fabulist of Buenos Aires. He wrote about the metaphysical and the physical aspects of Buenos Aires as well as tango, and I mention his story, The Aleph, at the end of the book. Tango itself has a rich lyrical tradition and the tango lyric is a genre in itself. Tango is really music plus poetry plus movement plus trouble."
Kassabova dances only occasionally now and is in a relationship with a Scottish art dealer who, by his own admission, has "two left feet".
"That's a blessing, considering what came before," she says. "But it's not about the feet, it's about your heart's desire and he doesn't have the desire to be in a darkened room with lots of neurotic people. Why would he - he's already got me!"
She enjoyed revisiting her past experiences for Twelve Minutes Of Love. "For the 10 months I was writing the book, I had the time of my life," she says with a smile.
"There's a term "tanguidad", which means being in a state of tango, a cocktail of agony and ecstasy. I was in that state. It was wonderful but you can't sustain it otherwise you'll become unhinged. Writing about it was like having the best dance in a way because I felt connected to everything that I have lived through in the last 10 years thanks to tango: all the people I've met, the friendships, the places I've been and all the long nights dancing and talking to some amazing characters, who have found their way into the story.
"That's why writing this book was a transcendent experience and I hope a little bit of it rubs off on the reader, a little will be enough."
But Kassabova is ambivalent about whether readers should take it up themselves. "That's up to them," she says. "There is a warning in the story because tango is a dangerous dance but it's also an invitation."
Twelve Minutes Of Love represents Kassabova's second foray into non-fiction after 2008's Street Without A Name, a fascinating account of growing up in Communist Bulgaria in the 1980s. Her third novel Villa Pacifica was published last year, but she has yet to embark upon her next.
"I don't know what I'm going to do next as I'm still recovering from writing this book," laughs Kassabova, who doesn't profess to prefer one form over the other. "A book like this appears on the surface to be more personal but the novel is also very personal. In fiction, you have to let your subconscious work and that always ends up being deeply personal in ways that you don't always understand as the author. This book was a joy to write, but fact and fiction engage different parts of you. I like the wilderness and the openness of fiction, and I also relish the honesty of non-fiction, the opportunity to just be yourself."
Twelve Minutes Of Love (Portobello, Allen & Unwin $39.99) is out now.
