MY COLDEST CASE YET...

WHAT'S not to love about a fictional detective with a quirky trademark? Think Morse with his crosswords and love of classical music, Poirot with his marrow growing and moustache maintenance, and Columbo who loved cooking chilli and tinkering with his old Peugeot.

- By Alison James

Yet none compare with Alex Ridley, the copper who croons at a jazz club when he's off duty. And what a voice the retired detective inspector has or rather the actor Adrian Dunbar, 67, who plays him.

But those with long memories will know this. In 1991, Adrian co-wrote and starred in the musical comedy drama film Hear My Song about Irish tenor Josef Locke.

"I've been interested in music all my life," smiles Adrian, who hails from Enniskillen in Northern Ireland.

"I formed a country music band with friends back in the 70s, was even an Elvis impersonator for a while and have played in many bands. I used to play bass guitar but I just sing now.

"It was a bit of a gamble incorporating a musical element into a serious police drama especially when you consider that a huge part of Ridley's back story is that he lost his wife and daughter in a fire. But it works.

"The songs, written by the fantastic singer-songwriter Richard Hawley, are really about male grief.

"They suit Ridley's character and what he's going through. Music brings him a certain solace. We're able to meld the songs into a kind of subtle comment about what's happening in each episode. They're a kind of reflection."

'I think it's important to show that you can move on from grief'

What also happens in every episode of this second series without fail is that Ridley wears the same battered, black leather jacket he donned constantly throughout the first.

A signature piece of clothing is another character-defining device much loved by writers of crime fiction from Vera and her unbecoming bucket hat to The Killing's Sarah Lund's Scandi-style Faroese jumper and Sherlock Holmes's iconic deerstalker hat. Adrian laughs in an it's-a-fair-cop kind of way when questioned about it.

"Well done on picking that up but, er, it's a brown jacket, actually," he jokes.

"It's police procedure so I really must pick you up on these details!