To audiences of the world-renowned Royal Opera House (ROH), in Covent Garden, Walthamstow resident Emma Turner is the measured voice announcing that tonight’s show will start in two minutes and reminding us to turn off our phones. To the cast and crew, Emma, as deputy stage manager (DSM), is an integral cog who oversees the whole production, from cueing up lighting and instructing huge flying pieces of set, right down to ensuring the singers are on stage on time (whether it be through 22 polite back stage calls or literally dragging them out of their dressing room, the petite blonde jokes).

Meeting the DSM backstage during the interval of a daytime performance of Tosca, it quickly becomes apparent that a calm head and the organisational traits of a filofax are key job requirements for this role, and, if Emma is any mark, energy and enthusiasm in surplus are also a must.

Stepping over wires, and negotiating the dozens of people working with military precision to turn the impressive set around before the curtain comes up, Emma proudly leads me to the place she calls home for up to 13 hours a day – the prompt corner.

No bigger than a square metre, the prompt corner is where Emma controls the performance via the various intimidating knobs, dials and buttons and her treasured prompt copy – a large red book containing the score and technical notes, which the LAMDA graduate refers to as “the bible”.

It is also where she will be sitting for next Wednesday’s performance of The Barber of Seville, which will be beamed live on various screens across the nation, including Walthamstow Town Square, a stone’s throw from Emma’s home.

“I’m trying not to think about the extra thousands of people watching (11,000 people attended the Trafalgar Square showing last year),” Emma, whose husband also works for the ROH, tells me. “I’m going to treat it like every other performance, and every performance is special.”

A comic opera by Gioachino Rossini, The Barber of Seville concerns the efforts of Count Almaviva to woo the beautiful Rosina without arousing the suspicions of the heroine’s overprotective guardian and the set reflects this light, fun, jovial story.

“I think Barber will translate really well onto the screen because it is so visually spectacular,” the Lincolnshire lass exclaims. “The music is great, there are loads of jokes and it’s lots of fun. I don’t like the term first-time operas, but this is one of the best if you’ve never seen opera before.”

In terms of job satisfaction, Emma insists “the more complicated the opera, the more she loves it,” adding Barber offers such a challenge.

“There are lots of exciting set movements and hydraulics to work with,” she reveals. “I’m not going to give too much away, but watch out for the Act I finale.”

The Barber of Seville will be screened live in Walthamstow Town Square on Wednesday, July 15, 7.30pm. Details: www.roh.org.uk/bigscreens