In my new book Masquerade, the heroine, Luz, is descended from an old and well-respected Andalucían family. But such is her manner that she usually avoids mixing with the aristocratic circles of the region, preferring instead quiet evenings spent with the same handful of friends, long walks in the countryside around Jerez and riding her mare.

To appease her parents, however, sometimes Luz must put on a beautiful dress and attend an event as one of the de Ruedas. Going to see a performance of the opera Carmen is no hardship, especially given that it is held at this spectacular theatre in Cadiz:

As her father puts it, the Gran TeatroFallain the Plaza Fragela is one of the notable monuments of Andalucía, a lovely example of the neo-Mudéjar style. It stands in the Plaza Fragela, in the north-west quarter of the Old Town, a grand and atmospheric theatre welcoming its visitors with beckoning mystery, like a magician inviting one to step back in time.

Inside, the theatre is the perfect setting for an opera attended by the gentry of Andalucía, with a handsome marble staircase, antiquated gold and claret décor, and ornate Moorish revival arches, all overlooked by a stunning nineteenth-century ceiling fresco, Felipe Abárzuza’s vast allegory of Paradise. Beautiful – but a little faded, Luz can’t help but notice. Her generation, the new blood of an emancipated Spain, is not represented here. This is an old world to which her parents belong, but not so much Luz.

In the family’s box, Luz scans the audience with a pair of opera glasses:

The lights were dimming, and she was on the verge of putting them down when she breathed in sharply. She found herself looking directly into another person’s pair of binoculars, a man seated in the box opposite. Luz just had time to notice the slow smile that curled at the side of the stranger’s mouth before the place fell into darkness. The curtain lifted and the first notes of Carmen’s overture resonated in the vast auditorium.

For the entirely of the performance, Luz is consumed by the thought of this strange man watching her. She is barely present, barely watches the show.

In contrast, a little earlier in the book Luz is a spectator of a very different kind of performance, one which holds her attention absolutely. She has found a gypsy encampment near her home, and hiding behind a large clump of bristling cactus, she watches a vibrant Romani spectacle of song and dance. Then, when night falls, a solo performance takes centre-circle. He is the gypsy who rescued her at the start of the book, and he is mesmerising as he strums the guitar and sings. The words are in Caló, the language of the gypsies, and Luz cannot understand them; but she sense that he is singing from his soul, laments of sorrow and misfortune, and declarations of passion and longing.

He sang in a kind of trance, as if reaching deep down into his soul to uproot the pain, drawing out the final notes in a prolonged, descending strain, with seemingly never-ending turns and tremolos. It was a haunting sound, so poignant Luz had great difficulty in controlling her urge to reach out to him.

Luz is supremely moved by the gypsy Leandro’s performance; in so many ways this is the show she wants to watch. This is where she wants to be, in nature, wild, impassioned: not in the theatre with the gentry watching performers pretend to be gypsies, but within the action itself.

But she does not belong in the gypsy encampment. As I write: she was not a part of these strange, passionate people, merely an onlooker, an intruder; she had no right to be there.

The two spectacles that Luz watches represent a difficult conflict in her character. She wants to be her own person in this new Spain, yet she cannot completely cast off traditions and what is deemed respectable for a young woman in the 1970s. She wants to follow her heart, but she cannot ignore the logic of the head.

Over the course of the book, Luz becomes torn between two men who symbolise this struggle between old and new, traditional and maverick, respectable and liberated. Andrés is the hidalgo, the gentleman – the kind of man who is respected in aristocratic circles and approved of by her parents. Leandro, conversely, is a gypsy, against whose people a great deal of prejudice exists; and how could Luz’s parents ever accept him, given their rocky history with the gypsies?

For Luz, falling in love forces a journey of self-definition, of who she is and what she will stand for. Does she want to attend the theatre and sit politely and silently as a performance unfolds, or does she want to stand in the circle of gypsies and stand and clap and chant her affinity with the performance? Or in fact is the very choice illusionary? Must Luz choose between one and the other; or can she find a way to embrace both?