As befits a bride so dedicated to the cause of gender equality, those trumpets will be loud enough not only to impress the millions watching around the world, but to shatter a glass ceiling along the way.
Lance Corporal Kate Sandford is to become the first woman from the band of the Household Cavalry to play the fanfare at a British Royal wedding, it is believed, as she joins an elite group of six on May 19th.
Joined by her husband, Lance Corporal of Horse Julian Sandford, the pair will, it follows, become the first married couple to play the extraordinary moment the bride arrives, unveiling her wedding dress to the world and allowing Prince Harry his first glimpse.
The State Trumpeters, who wear the distinctive gold jackets of the Band of the Household Cavalry, regularly play at major state occasions where the Queen is present, as well as at national events and anniversaries.
Women were allowed to join the band in the mid-1990s. While it does not keep official records based on gender, long-serving members of the band cannot recall a woman ever taking the prestigious role at a Royal wedding before.
The involvement of L/Cpl Sandford will be particularly significant for the wedding of Prince Harry and Ms Markle, who both identify as feminists who care deeply about gender equality.
The day will no doubt also bring back happy memories for the Sandfords, who married in December to a fanfare played by their own colleagues.
To have my wife with me, who’s worked so hard to get on the trumpet team and represent females in the army... I’m very proud of her
L/Cpl Sandford, who joined band five years ago, said it was a “very big privilege for me to be able to represent the females”, adding that being recently married adds a “nice aspect” to the day.
“It’s very very exciting,” she said. “I feel very proud. I’ll be very excited on the day but you’ve got to keep your head on your shoulders and play to the best of your ability.”
When she first joined the State Trumpeters, performing at state banquets, she said she would often hear guests remarking incredulously: “There’s a lady!”
“They were taken aback by it,” she said.
“It’s brilliant that it’s the norm now.” Saying she “very much hopes” it will make a difference to other women hoping to make it to the top of the Army’s bands, saying she had benefited from male role models who pushed her onto the next level.
Her husband added of the wedding day: “I think personally it’s just a really proud moment to represent Britain at its best, and show how it does pageantry.
Wedding at Windsor Castle
“For me it’s an honour to play at such an occasion. It’s going to be the pinnacle of my career so far.
“To have my wife with me, who’s worked so hard to get on the trumpet team and represent females in the army... I’m very proud of her.”
The couple and their comrades have been practising the as-yet-unconfirmed fanfare for weeks in secret conditions under the eye of Trumpet Major Matthew Screen.
Similar in height, it is likely that the pair, who met in the Household Cavalry and married in small Leicestershire village in December, will stand next to each other at St George’s Chapel.
Insisting they are not obliged to be “attached at the hip” at work, Julian said: “We don’t get sick and tired of each other.”
Asked whether Ms Markle was aware of the blow her trumpeters will be striking for gender equality, L/Cpl Sandford said: “I wouldn’t think she does.
“We haven’t done any trumpet engagements where Ms Markle has been present so far, although it [the news] might work its way down the pipeline.”
Her husband added: “If she’d seen her I’m sure she’d remember her."
Not that they will be drawing attention to themselves on the day.
Due to play from the organ loft, Trumpet Major Screen said: "We will definitely be heard but not seen."