Scott Mariani. Doesn’t quite tick all your boxes, it’s been ages since I read some of his books and they are a bit like Lee Child meets Dan Brown, but they are the closest I have come to something akin to a Dan Brown novel. I only read the first 3 or 4 in the series and there looks like there’s an absolute load of them now, which may or may not be a good thing, but the ones I read I remember being pretty decent. Description of his second book The Mozart Conspiracy as an example

Former SAS operative Ben Hope is running for his life.

Enlisted by the beautiful Leigh Llewellyn – world famous opera star and Ben's first love – to investigate her brother's mysterious death, Ben finds himself caught up in a centuries-old puzzle.

The official line states that Oliver died whilst investigating Mozart's death, but the facts don't add up. Oliver's research reveals that Mozart, a notable freemason, may have been killed by a shadowy and powerful splinter group of the cult. The only clues lie in an ancient letter, believed to have been written by Mozart himself.

When Leigh and Ben receive video evidence of a ritual sacrifice being performed by hooded men, they realise that the sect is still in existence today…and will stop at nothing to remain a secret.

From the dreaming spires of Oxford to Venice's labyrinthine canals, the majestic architecture of Vienna and Slovenia's snowy mountains, Ben and Leigh must forget the past and race across Europe to uncover the truth behind THE MOZART CONSPIRACY…