Nuns were singing in Oxford’s Wesley Memorial Church. Nothing remarkable about that, surely? But these were not real nuns, and perhaps the song Climb Ev’ry Mountain doesn’t hit the Wesley Mem rafters every day.

The explanation? The church had temporarily transformed into a launch pad for the New Theatre’s Christmas show, Rodgers and Hammerstein’s phenomenally successful musical The Sound of Music.

The production of The Sound of Music coming to Oxford was a trailblazer when it opened at the London Palladium four years ago. Never before had a leading West End role been cast by means of a TV reality show.

Called How Do You Solve a Problem Like Maria? the show came complete with the obligatory panel of scary judges — although one of them, The Sound of Music producer David Ian, would never do on The X-Factor: he actually smiled at the contestants.

Sitting in a Wesley Mem pew, David looked back.

“I went into the TV show thinking, ‘I’m just doing my job, I’m casting, it’s what I’ve done for the last 20 years’. Then I thought, ‘help — I’m performing too, this is a blast back to my days as an actor’. The show genuinely surprised us — it was booked as a filler programme by the BBC for the quiet months of May and June. But it ended up with an audience of nine or ten million. ”

The winner was Welsh singer, Connie Fisher, who has now sung the role of Maria, governess to the von Trapp family, more times than she can remember.

When we met in the Wesley Mem vestry, Connie immediately dropped a bombshell.

“My last ever performance as Maria will be in Oxford. I’m kissing the role goodbye. It’s a really big thing for me. January 2 is my final show.”

So it was rather an appropriate moment to look back to the beginning, and the razzmatazz of How Do You Solve a Problem Like Maria?

“I still meet people who remember voting for me,” Connie told me with undimmed enthusiasm. “I like meeting them at the stage door because they don’t realise how much of a golden ticket they gave me by spending 35 pence on a phone call. I do offer to pay their phone bills!”

You don’t have to talk to Connie for long to sense that beneath a strong sense of fun, her feet remain firmly planted on the ground.

How, I asked, does she keep the role of Maria fresh, playing her night after night?

“I’m very forgetful. I forget what I did yesterday, but it must have been The Sound of Music! It’s very like Groundhog Day, being in a musical. But you never know who you’re working with, because the kids change every four shows. It’s great fun working with them, because they are magically unpredictable. One of the Gretels is so upstaging, she kills all my laughs, it’s wonderful. And she’s only six.

“So you think, ‘who’s on tonight?’. Working with different actors, you get different tensions, you get different thoughts coming at you. That keeps it fresh.”

In the show, Maria ends up marrying the taciturn Captain von Trapp. But Connie Fisher has just had a fairytale wedding too. In true Brief Encounter style, she met her future husband by chance on a Cardiff train station platform.

“We only spoke for seven minutes, and I didn’t give him my name. The only hints I dropped were that I’d won a TV contest to be in a new show, and that I was Welsh.

“He was going to play golf with a conductor, and told him that he’d met this girl. The conductor said, ‘It must be Connie Fisher’, and trainman, as I’d started to call him, said ‘who?’. They Googled me and, embarrassingly, I was wearing the same dress in the Google picture as I wore on the platform, so they knew it was me.

The conductor remembered that the opera singer Bryn Terfel had my number — we’d sung at a festival together. Three long weeks later Bryn called me, and my first dinner with trainman was arranged.”

The Sound of Music is at the New Theatre, Oxford, from December 7 to January 2. Tickets 0844 847 1585 or at the website newtheatreoxford.org.uk