Have you seen the musical Guys and Dolls? It’s a favourite of mine, because it’s upbeat and atmospheric and has toe-tapping tunes; plus there’s a wonderful cast of Hollywood greats in the 1955 film version: Marlon Brando, Jean Simmons, Frank Sinatra and Vivian Blaine. And of course, hopeless romantic that I am, I love the musical because it’s all about love.

One of the most interesting elements in the story, I think, is the exploration of how a person falls in love. Is it a choice, carefully considered, or pure chemistry?

Gambler Sky Masterson is a risk taker who can’t avoid a bet – even when it’s a challenge to seduce a woman who’s the very antithesis of all he stands for: Sarah Brown, a sister at the religious Save the Soul Mission, and as straight as they come. On their date together, the pair discuss what love means in the song ‘I’ll know’.

Sarah is careful, measured – a planner. She sings of her dream man: ‘I’ve imagined every bit of him/From his strong moral fibre to the wisdom in his head/To the homey aroma of his pipe’ and ‘I’ll know by the calm steady voice/Those feet on the ground/I’ll know as I run to his arms/That at last I’ve come home safe and sound’.

Sky, meanwhile, lives his life as a gambler trusting to Lady Luck, and according believes in love at first sight – a connection beyond control. ‘Mine will come as a surprise to me/Mine I leave to chance and chemistry…/Suddenly I’ll know when my love comes along/I’ll know then and there… /I’ll know and I won’t ever ask/Am I right, am I wise, am I smart’.

The core of the difference of opinion between Sky and Sarah is that one believes successful relationships are based on chemistry, and the other on compatibility. In her article ‘How Much Does Chemistry Count?’, Kimberly Dawn Neumann explores the question: What’s more important to a successful relationship, chemistry or compatibility? She asks various people. A newlywed couple rate chemistry as more important; a single man rates compatibility as more important; an author of a book on passion believes both are equally essential.

In Guys and Dolls, the fact that the pair fall in love and marry, despite Sky being so different to Sarah’s dream man, says a lot about the power of chemistry. The same message comes through in my novel Burning Embers. Rafe and Coral are drawn together, often against their wills, by a powerful, burning passion. It’s the chemistry that makes the connection; then the two must find a way to be compatible so that they can make one life together.