As tenor Joseph Calleja takes to the stage of London’s Royal Albert Hall for the prestigious Last Night of the BBC Proms on Saturday, his most faithful fan will be supporting him in the audience.

It’s a gift. He’s special. He’s Joseph

Octogenarian Colette Males first saw Calleja perform in 1999 and over the past 13 years has followed him all over the world: to opera houses, concert halls, his mother’s home and on family holidays.

Before she met Calleja, friends had been telling the opera fan she just had to see the young tenor. She watched him for the first time in The Barber of Seville in Washington when he was only 21.

“When I listened to his voice, it was so sensuous, so mellow, just like honey pouring down. I got goose bumps all over – mind you, he still has that effect on me every time I hear him sing, no matter how many times I’ve watched him over the years.”

She was instantly hooked and after that performance went backstage to speak to him.

“I did not expect him to be such a young, good-looking fellow! He was ever so nice – but my daughters thought I was crazy to follow so many of his performances,” she laughs.

At the time she worked with the US Department of Defence in Belgium, and whenever he performed in Europe, she’d jump on a plane to watch him.

“After two years of doing that, we became friends. We’d go out for dinner sometimes together after I attended one of his performances – we looked quite a pair, I can tell you, this young man with me; I could be his granny!” she laughs.

Ms Males, who is originally from France but moved to the US when she married an American, took over the role of Calleja’s French language mentor, which has been of great help to the tenor as he has taken on French roles, such as the lead part in The Tales of Hoffman at New York’s Met.

“I started speaking to him and corresponding with him in French – and still do to this day,” she says.

Since meeting the tenor, she has been taken in by the entire Calleja family. “I feel part of them now. They are such a lovely, warm family – I consider them as my second family,” she says.

Although she is based in the US, where she has two sons and two daughters, she visits Malta frequently and has become particularly close to the tenor’s mother, Rita.

“Malta reminds me of the past. Family is still so important here. The speed of life is different,” she says.

She dotes on Calleja’s two young children.

“My grandchildren are now all grown up, so Xandru and Clara are the loves of my life.”

She recalls when one day she bought Clara, who was then only two, a DVD of the ballet La Bayadère: “There was no stopping her from dancing ballet after that.”

However, Ms Males hopes that the tenor passes on “his gift” to one of his children.

Ms Males claims she is no opera expert, but she is being modest. She watched her first opera – Samson and Delilah – when she was 14.

“My uncle was a musician, so we all had to tag along. I hated that one, but over the years I grew to love opera.”

Whenever she can, she follows Calleja performances, sometimes watching the same performance on different nights.

“It’s different every time: a performance depends on so many things. You have to wait for all the right elements to be there.”

One of her favourite performances was his part as the lovelorn Rodolfo in Puccini’s La Bohème at London’s Royal Opera House. Calleja, she says, managed to get the audience carried away with his part.

She loved him as the king in Bohème, “but we had to hate him as the Duke in Rigoletto,” she says.

“When he came out with the cape flying, and that voice... Oh! That was so powerful.”

She says there are other good tenors in the world – but Calleja’s voice is very particular. “It’s a gift. He’s special. He’s Joseph.”

Calleja at the Last Night of the Proms

This is the fourth year running that Calleja will be taking part in the BBC Proms, but it is the first time he has been invited to sing the highly prestigious Last Night.

This year he will be joining conductor Jiri Belohlávek and the BBC Symphony Orchestra to perform a mix of popular opera arias and classic songs, including Rule Britannia.

He will also be giving a sneak preview of his forthcoming album Be My Love.

The Last Night of the Proms is usually the preserve of British artists, and Calleja is one of the few foreign guests to have been invited.

The show is famous for the artist’s sartorial choices and it is not the first time that soloists have decked themselves out in British patriotic colours, although Calleja would reveal nothing about his costume.

After describing Calleja as “the great Maltese tenor”, The Sunday Times of London art critic Hugh Canning wrote in an article last month: “He is only 34, but his name has been lauded in the British press since the late 1990s.”

Mr Canning added he “should be around to delight us with his sunny Mediterranean voice and personality for years to come”.

Calleja has also been shortlisted for The Gramophone Awards, one of the most significant honours bestowed on recordings in the classical music industry.

The winner of the awards is expected to be announced on September 27.

• On Tuesday, Calleja will be a guest on the BBC Breakfast programme at 8am GMT. The Last Night of the Proms concert will be broadcast live on BBC1 at 7.30pm GMT.