Van Morrison is all set for Blenheim Palace ball

One of the most prolific singer-songwriters of our time, with a formidable back catalogue – and a reputation to match.

Later this month the Grammy, Brit and Ivor Novello-winning artist returns to Blenheim Palace to headline the first of its Nocturne shows.

The timing couldn’t be better for Van – who previously played the palace in 2004. Earlier this year he released his 35th studio album. But while most previous efforts have focussed on his own abilities as a recording artist, this one is different.

To be honest the clue is in the name: Duets: Re-Working the Catalogue does exactly what it says. Van teams up with a hand-picked selection of guests to record a handful of his more than 360 songs. It is not just a trawl through his greatest hits though.

With the help of artists like Bobby Womack, Steve Winwood, Mark Knopfler, Taj Mahal, Michael Bublé, and Clare Teal, he revisits some lost gems – giving them a fresh shine.

The album, which also features Mavis Staples, Natalie Cole, George Benson, Gregory Porter (who joins him on at Blenheim), PJ Proby, Joss Stone, Georgie Fame, Mick Hucknall, Chris Farlowe, and his own daughter Shana Morrison, was recorded in London and his home town of Belfast.

“The idea has been around for years really,” he said. “It’s what you call a side project. I had to leave a lot of people out because of the time factor and it was going to run into a double or triple album. I just had to get people who were available.

“It started back in October 2013. I wanted Bobby Womack, he had been one of the first people on my list for many years. So when Bobby, Mavis Staples and Natalie Cole were playing the Blues Festival in London and so was I, it made sense to get them during that. Those three kind of kicked it off for me. Then it was much harder to get the rest of it because of calendars.”

He insisted, where possible, on recording face to face with his guests in the studio.

“It is not always possible because of calendars, as people are all over the place and very busy, but whenever possible you want to get that.”

He worked quickly, proud of his ability to just get the job done. “I’m from the John Lee Hooker school of, ‘you get in, you get out’, kind of thing,” he says. “If you have the people available, like George Benson, you can do a great couple of takes and be out of there having lunch by 3pm.”

He consciously steered clear of the hits – songs like Moondance and Brown Eyed Girl.

“There were two parts to it,” he says. “One was the fun of doing duets the other was re-working the songs as no one else is working them.”

He admits it was tough to make a short list of songs. “It was very difficult. Some of them picked their own songs or I made suggestions and they said that was fine - like Bobby Womack; I sent him that track and he said ‘yeah I like the song I can do that’. Other ones had songs in mind, like Mick Hucknall wanted to do Streets of Arklow, he specifically picked that song. Mark Knopfler also picked his song (Irish Heartbeat). Of course the PJ Proby one (Whatever Happened to PJ Proby) is pretty obvious - so that was an easy one.

The album starts with Bobby Womack, who died aged 70, this time last year. “I am lucky I caught him in time really,” says Van. “He looked pretty good at the time. You wouldn’t have known he was very ill, not visibly anyway.”

Of particular interest to Oxfordshire fans is his collaboration with Gregory Porter, who supports him for Nocturne.

“I really like his voice and I like his material,” says Van. “He is a great songwriter in his own right. I first heard him, singing 1960 What? on the radio several years ago. It’s great.”

While enjoying the duets, he admits it was a struggle to pick the artists – and the songs.

“It’s not only difficult picking people because there are so many of them, it’s also difficult picking songs. You are working from 350 songs and that is extremely difficult also to work out what songs we are going to do. I don’t really ponder past stuff unless I want to kind of maybe redo it or do a different arrangement. Part of it too was doing them a little bit differently.”

Palace date: The Nocturne show is a rare opportunity to hear the musical legend live outdoors

For a man who has traded in blues, jazz and soul, what does he think about the current state of R&B?

“Terrible!” he says, not holding back. “I can’t relate to it now, what they call R&B. It doesn’t have any rhythm in it. It doesn’t have any blues. To me it is very un-rhythmic. Its very robotic. I don’t know what that is. Words take on different meanings after a while.

“It’s like soul, I don’t know what that is now. It is just a word, it can mean anything.

“What is jazz?” he goes on. “Some of the stuff that they say is jazz, I don’t know what it is. Blues also. Something started with Jimmy Hendrix. So the jumping off place was really loud guitar and feedback, then that became the blues. To me that’s not blues, blues is like Junior Wells and Buddy Guy in a club, live.”

The Blenheim show follows a date, up the road at Cornbury Festival, at Great Tew, two years ago. Though he admits he prefers more intimate sets. “I have always liked small gigs,” he says.

“Plus I don’t like travelling. I never have, especially long distance travelling. I like it even less now because I am tired now. I don’t like booking things way in advance either, because sometimes you get there and you’re not in the frame of mind to do it or too tired.

“I like to be able to book things at short notice as much as possible. I can’t do tours anymore, I can’t do it. It’s too exhausting.”

He prefers, he says, to have contact with the audience.

“It’s about playing and singing rather than performing. It’s more direct and there’s more communication.

“You have to keep it spontaneous, otherwise it gets boring doesn’t it?”

*Duets: Re-Working the Catalogue is out now

Van Morrison plays Nocturne at Blenheim palace on June 25. Tickets available from nocturnelive.com. VIP packages also available. Prices start at £60