Mr Sridharan Madhusudhanan's wife first fell in love with a song from Wakin Chau 20 years ago.

The couple went on to buy the Taiwan-based Mandopop singer's albums but had never seen the artist in the flesh.

Mr Madhusudhanan is India's top envoy to Taiwan.

But, early in November, the couple finally met their idol, not that Mr Madhusudhanan was initially aware that the man he was introduced to is the celebrity.

They were at an event in Taipei to celebrate the works of Nobel Prize-winning poet Rabindranath Tagore, according to the Focus Taiwan portal.

Recalling the encounter, Mr Madhusudhanan posted online: "Today, at the Red Room event, while I was on stage, a tall figure came and sat in the front row.

"During the short intermission, my friend introduced him as her husband.

"We didn't even share our names and moved on."

When he was heading back to his seat, another friend asked Mr Madhusudhanan if he recognised the man he just met.

Only then did it dawn on him that the man is Chau, 58.

He asked his wife to sit next to Chau and asked the singer to tell her his name.

The couple shared with Chau that they had, in particular, loved his song Peng You, which means "friends" in Chinese, for decades.

"Now that we've become peng you, our families have decided to catch up over an Indian dinner soon," Mr Madhusudhanan said. "Of course, we'll chat about music."

In his Instagram post, he revealed that his wife was in a taxi in Beijing 20 years ago and was intrigued by a song playing on the radio.

"No clue about the song's name or singer. So she (went) to all the music shops in Beijing, and to the amusement of the shopkeepers and onlookers, start humming the tune and ask for the CD.

"Except for the free entertainment that we gave to the Beijing scene for a few months, nothing changed - still no clue about the song or singer."

But her perseverance was rewarded when she hummed the tune to another driver, who was able to solve the puzzle.

"She came home with a CD of Emil Chau."

The singer took that stage name in those days.

Of Peng You, Mr Madhusudhanan wrote that it has a big impact on his family.

"We woke up to it, we relaxed to it, we ate to it, we danced to it.

"Our kids grew up listening to that song every day."