Silver-plated trumpets built in a converted cow shed in North Yorkshire will be played to herald the marriage of Meghan Markle and Prince Harry.

The village of Sheriff Hutton, near York, is not where you would expect to find instruments fit for royalty being delicately handcrafted.

But this is "trumpet central".

"It's a beautiful cow shed in a very nice part of England," trumpet aficionado Richard Smith said with a laugh.

Mr Smith runs his company Smith-Watkins from his home — hence why the renovated cow shed is the factory.

Not that there are a lot of staff.

It is just Mr Smith and technician Richard Wright.

The order from the Ministry of Defence for 20 new trumpets came in earlier this year.

Richard Wright said silver rings and the royal coat of arms were requested. ( ABC News: Lisa Millar )

A prototype was built and requests for improved acoustics incorporated.

"They did want a bit more bling on the instrument — more silver rings and also the royal coat of arms so the whole instrument would last 20 years irrespective of which monarch is on the throne," he said.

The pressure is on Mr Wright who carefully solders, bends and shapes the materials into gleaming trumpets.

"It's a special instrument that's going to be kept; not just for the wedding, it's a state fanfare trumpet," he said.

"You have that thing where you want it to be as perfect as it can be."

There are 42 parts to each trumpet and if Mr Wright built one instrument from start to finish it would take a week.

But he does them all in stages and said it was like a hobby, not a job.

Mr Smith and Mr Wright's trumpets have been used during the London Olympics and the wedding of Prince William and Kate Middleton in 2011.

They were part of the celebrations for the Queen's Diamond Jubilee in 2012.

And now they will be played at the eagerly anticipated wedding in May.

Richard Smith demonstrates a trumpet handcrafted by his company Smith-Watkins. This kind was used in the 13th century and could be as long as six feet. ( ABC News: Niall Lenihan )

The two men will not be caring about dresses or celebrities. They will be listening for their trumpets.

"To the average person listening, it probably sounds absolutely fantastic, but for me and Richard we can always tell if there's a slightly dodgy note in the middle or at the end," Mr Wright said.

He is quick to add it is never the instrument's fault — always the player.

The "natural" or herald trumpets are notoriously hard to play. They do not have valves, and the banners with the royal emblem hanging from them make them even heavier.

"They can be standing there not moving at all for maybe an hour-and-a-half, and then at the right moment they have to put the trumpet to their lips and it has to be perfect," Mr Wright said.