As one of the most gifted singers of her generation, Amy Winehouse sold millions of albums and captivated audiences with a powerful voice that belied her tiny 5ft 3ins frame. Yet Amy’s many troubles included doubting her immense talents.

And on the night before she died in 2011, aged just 27, the singer was still questioning the ability that powered huge hits such as Rehab, Valerie and You Know I’m No Good.

One of the singer’s closest confidantes was Dale Davis, the bassist and musical director of her band throughout her live performances over the years. Despite talking almost daily to the singer, Davis didn’t know just how gravely ill Amy was when they spoke on the phone on July 22, 2011.

The bassist believes she might finally have begun to appreciate her incredible talent when she called him.

Recalling that bittersweet final conversation, Davis tells the Sunday Express: “Amy rang me and said, ‘Dale, I’ve been watching myself on YouTube. I can sing, can’t I?’

“I told her, ‘Of course you can. You’re the best!’ Amy really was the best singer, in my opinion. And I’m glad she acknowledged it then, because I thought, ‘You’ve never, ever said that before’.

“When you’re that great, but you don’t talk about how good you are – Amy must have struggled deep down if she didn’t know how to say it.”

The next day Amy was found dead at her home in Camden, north London. Davis was devastated. And 14 years on he reveals he’s still shocked – especially as her health had seemed to be improving in the weeks before.

Davis had last seen the star two evenings before her passing. She had phoned him to say: “Come on, Dale, let’s hang out.” Davis recalls: “We spoke for a good hour. Amy was excited about the record label she’d just started, to release her goddaughter Dionne Bromfield’s music.

“We talked about so many different things that night. Seeing how Amy was that night, her death doesn’t make sense. It was the best Amy had looked since she was young. It makes it even more confusing that it was the final night I saw her.” Officially, Amy’s death was attributed to alcoholism. But Davis believes it was the star’s battles with food which killed her.

“For me, Amy’s eating disorder is what finished her off. She just didn’t eat for the last five years,” he sighs. “Food was difficult around Amy. I’d sit with her and feel guilty for eating a big plate of food. One day, Amy told me, ‘Dale, you’re always eating!’

“I replied: ‘Yeah, I need it. It’s energy.’ I don’t have a problem eating, so I could never really understand why someone couldn’t eat. It’s ignorance on my part, but I couldn’t get my head around Amy not eating.”

Her battle with drink and drugs have been well-documented, but another less well-known major problem the singer had to cope with was insomnia. After her husband Blake Fielder-Civil was jailed for 27 months in 2008 for assault, Amy struggled to sleep.

Davis explains: “Amy’s sleeping patterns disappeared once Blake went to prison. She couldn’t really sleep, which affected her nervous system. When you’re on tour the whole time, you get tired. And when you’re tired, the demons come out.”

Despite Amy’s demons, Davis loved his role in overseeing her backing band and is grateful he got to see the singer’s formidable talents up close. A former bassist for talents including Tina Turner, Paul Young and Norman Cook, Davis was recruited as Amy’s musical director in 2003, the year of her debut album, Frank.

It was at their third concert together, at Notting Hill Carnival, that Davis first appreciated the singer’s ability. Davis, an affable and enthusiastic presence over a video call, enthuses: “Carnival isn’t theeasiest place for a young, white singer to come across. But by halfway through her show, loads of people were turning up. By the end, I thought, ‘Your singing is so powerful, you don’t need a microphone.’ I realised then, Amy was a very special talent.”

Their friendship was cemented during Amy’s first nationwide tour.

She was supporting jazz singer Jamie Cullum when the tour manager wanted to go home early one evening.

Davis told him: “It’s Amy’s first tour. We’ve all got to work here, why don’t you join us and relax?” As he remembers now: “Amy realised then that I had her back. After that, she always said we were the mum and dad of a tour.”

Even during her lowest ebb, Amy would look after her band and road crew, trying to ensure they were at their best.

“Amy was a very spiritual person, which most people don’t realise. She could really connect with people. She always wanted to know how you were, not how she was.

“Amy didn’t want people to make a fuss of her. She’d appreciate it, but she was very shy about her feelings. Through all her problems, when you could see she had issues going on, Amy never wanted to talk about those.”

Davis was a musical consultant on last year’s biopic, Back To Black, which sawrising star Marisa Abela play the singer.

The bassist laughs when asked what Amy would have made of the film, saying: “She’d have been embarrassed and asked, ‘What are you doing, making a film about me? What’s all the fuss about?’”

That diffident attitude to her talent is wrapped up in Amy’s rebellious nature.

She remains an icon to female singers, blazing a trail for women in music to be uncompromising.

“By doing her own thing, Amy was an influence. She was rebellious and had a punk attitude, and a lot of successful female singers have taken on Amy’s attitude.

“She gave women a chance to be themselves. You don’t have to sound like Amy musically but, if you take her spirit on, you’ll move on. Amy just wanted people to enjoy themselves.”

For the past eight years, Davis has honoured Amy’s legacy by performing with her other backing musicians, playing shows as The Amy Winehouse Band, fronted by young singer Bronte Shande.

As Davis says: “A lot of younger people are coming to see us. It’s as close as they’ll get to experiencing Amy live.”

Some shows on their forthcoming tour feature an orchestra, but Davis admits: “Amy never liked having an orchestra. She thought it diluted her sound. Amy wassinging in a scene that was heavily male-dominated and she wanted an edge.”

In concert, Amy excelled at improvising the arrangements of her songs. That made it tough for her band to keep up. We let Amy do her own thing. Amy was never a person to sing something twice the same way.

“She’d change a song for four shows in a row, until by show five it’d settle for a while, and then she’d change it up again. Amy was a very courageous performer, which contributed to her burnout. When you’re performing to that level, on the big platform Amy had, you’re giving so much that you aren’t getting the rest you need.”

Amy’s second and final studio album Back To Black was released in 2006.

Davis reflects: “She’d been singing the same songs for five years before she died. When you’re an improvising artist, you’ll burn out. The songs meant less to her those years later. Sometimes, you want to be an artist, not a ‘star’. That was hard for Amy.”

Amy’s final concert was in Belgrade on June 18, 2011, a month before her death. It was so chaotic the remainder of the planned tour was cancelled.

Davis says of that gig: “It was the toughest show I’ve done in my life. Amy just didn’t want to be there. It was the first time Amy didn’t make an effort to sing. She always made an effort to sing, but at that show she was too distracted.

“Coming off stage, someone told me we’d been on for 80 minutes. I said, ‘I only remember the first few minutes.’ My body must have gone into shock. Once we called off all the gigs, Amy relaxed.”

No-one will know how far Amy could have taken her talent if she had lived beyond her struggles.

She wrote a third album of material which remained unrecorded.

“Her producer Salaam Remi said all the material was there. But Amy never had chance to record it.”

Today Davis believes Amy could have gone on to be a success as an actor or a TV presenter. ?Intriguingly, the singer was interested in pursuing alternative careers. Davis says: “Amy was an all-round entertainer. In 2007, Amy told me: ‘I fancy a bit of acting,’ and I can see she’d have been brilliant. She could have had her own TV show too, as Amy was one of those people who’d have been good at whatever she turned her hand to.”

At least the small but perfectly-formed body of work Amy did release will live on.

“Amy still has an effect,” smiles Davis. “Someone that impactful will touch people’s lives for a very long time.”

The Amy Winehouse Band tours from November 1 to December 19. See ticketmaster.co.uk for full dates and tickets