It has been a little more than seven years since she last appeared here – “too long ago”, she says – during which time she has released three studio albums of her own, as well as branching out as a producer for Barbra Streisand on her 2009 Love is the Answer album. She also led the band on Paul McCartney’s 2012 CD Kisses on the Bottom.

Of the Streisand project, which went to No 1 on the Billboard albums chart, she says it was “an unbelievable experience”, but one that left her in no doubt that she belonged on a piano stool rather than in the producer’s chair.

“I prefer being in the piano/band leader/arranger role. I loved it and I felt very happy, but of course you are also looking at Paul McCartney, and how fun is that? Looking back I sometimes can’t believe I got to do that, and working with him and Tommy [LiPuma, who produced the record] we had such a good time. Those things don’t come along very often, so I’m grateful for that,” she says.

It is striking that Krall, whose albums have sold more than 15 million copies worldwide, still uses the language of the fan when talking about other artists. She has her jazz heroes, of course, but many of the people she deeply admires come from the pop and rock worlds. The title track of Wallflower is a relatively little known Bob Dylan song.

“I met Bob Dylan once and I said ‘I really like the way you play the piano’ and he said ‘Well, you should know ‘cause you’re a piano player’. I was like ‘How do you know that I play the piano?’ He’s unbelievable. I love him. Joni Mitchell as well. Those people I hold in high regard – they’re like Miles Davis to me. You know they exist but when you see them …

“I’m like that with Paul, but he makes you feel so much at home and relaxed. [When meeting those artists] I just go back to feeling like a 16-year-old kid. It’s a good way to feel. I’m glad that I’m 51 years old and I still feel as excited about music as I did when I was 16.”

Some of that excitement can be heard on the Wallflower album – originally released in February last year and re-released last September in an expanded 20-track version. Both releases include a new McCartney song, alongside 1960s and ’70s hits from the Eagles, 10cc, and The Mamas and the Papas, among others.

Fellow pianist David Foster produced Wallflower, and performed most of the piano parts, leaving Krall free to concentrate on her vocals, overdubbing the occasional piano solo.

“We decided that we would not try to make the songs into jazz songs, so we didn’t really change the harmonies too much from the originals. We just tried to make beautiful arrangements and interpretations of them, and I think David did an amazing job with the orchestrations, but we stayed true to the songwriters’ original melodies and chord changes,” she says.

The McCartney song, If I Take You Home Tonight, was originally recorded for the Kisses on the Bottom album, but not finished or released.

“I found the sheet music from that session on my piano one day, and I always loved it. Karriem Riggins who is playing drums with me – he’s on that record as well – said ‘Diana, you should just ask him’ so I asked Paul if it was OK [to record the song]. He said ‘Sure’ and I think David’s arrangement is just spectacular. I’m really happy about having a new song by Paul McCartney on my record. It’s not just songs of the ’70s, it’s songs that work together and make a piece.”

It is playing those songs and the many others in her repertoire live with her current road band, however, that most excites her at the moment. She came back strongly to the concert circuit last year after some enforced time out in 2014 suffering from pneumonia.

“I’m doing much better now. I’ve been back on the road for the last year, and we just haven’t stopped. On bass we have Dennis Crouch, on drums Karriem Riggins who I’ve worked with for almost 20 years, keyboardist Patrick Warren, fiddle player Stewart Duncan, and Anthony Wilson on guitar. I play piano, so there are six of us.

“It’s really fun and we’ve been playing together now for almost five years. I’m listening to the band to the point at which I sometimes forget that I’m in it. It’s so thrilling to hear everybody play together.”

The hardest aspect of life on the road, she says, is separation from her husband, Elvis Costello, and their nine year old twin sons – “the music is the easy part”. However, she and Costello have the same management, which tries to harmonise their schedules, and the children are in a school that is understanding about them accompanying their famous parents on the road from time to time during school terms.

Costello and Krall collaborated on some of the songs for 2004’s The Girl in the Other Room, and he appeared under the pseudonym Howard Coward on 2012’s Glad Rag Doll, but no joint recording projects are planned.

“I’m happy if we can just sit down to dinner together, but there’s music going on in the house all the time. It would be amazing if we could do something again. I’m sure it will happen, but we’ve both had really busy years. It would be something to look forward to. He’s amazing. I’m lucky.”

In the meantime, if the reviews for the last year’s shows by Krall and her band are anything to go by, her Hong Kong concert is also something to look forward to. “It’s a very different show. It’s so much fun and the band is just off-the-charts fantastic. It’s such a joyful musical ride we take every night.”

Diana Krall, Jan 24, 8pm, AsiaWorld-Arena, HK International Airport, Lantau, HK$480-HK$880, HK Ticketing. Inquiries: 3128 8288