We’re walking round with a briefcase full of good news here, the best parts of American decency and what democracy was

Bill Murray and a chamber trio led by his friend, cellist Jan Vogler, are travelling the world sharing their love of poetry and music. It’s a positive celebration of American values, the Hollywood star tells Janet Christie ahead of their Edinburgh show

Back in 2013 Bill Murray was about to board a flight from Berlin to New York and noticed another passenger carrying a large box. Or as the star of numerous blockbusters from Ghostbusters to Groundhog Day tells it, “Uh, I saw this fella carrying an oddly shaped box, and I said ‘are you going to fit that thing in the overhead locker?’ And he looked at me like I was braindead, and said ‘it has its own seat’. And not only does it have its own seat, but it has its own seat in first class. And it has the window seat.” He laughs. “Just another thing I don’t know anything about – how you travel around with a Stradivarius cello.”

The fella was Jan Vogler, internationally renowned German musician, the cello was a 1707 Stradivarius and the trio hit it off on the flight. Back home in New York they became friends, mixing it up in New York’s cultural melée. “He heard me play Bach, I heard him read Whitman,” says Vogler. Then Murray invited Vogler on an organised poetry walk across the Brooklyn Bridge and the idea for the show, New Worlds, which they perform in Edinburgh on Monday, was born.

Billed as an encounter between the great music and literature that showcases American values and builds cultural bridges between the US and Europe, it features works by Twain, Hemingway, Whitman, Bach, Bernstein, Gershwin, Van Morrison and Tom Waits. Murray handles the vocals, songs and poems, with music, from Vogler on cello, his Chinese wife Mira Wang on violin and Venezuelan Vanessa Perez on piano.

It’s a little left-field, something unexpected, unpredictable, exactly what you’d expect from Murray who has long segued happily from comedy classics like Ghostbusters and The

Royal Tenenbaums to co-writing and starring in a Somerset Maugham adaptation (The Razor’s Edge in 1984) or singing Roxy Music’s More Than This in a Tokyo karaoke bar in Lost

in Translation. He even turned up washing dishes at a student party in St Andrews after a celebrity golf tournament. Maybe Bill Murray performing The Bonnie Banks o’

Loch Lomond with a classical trio is exactly what you’d expect him to be doing on a Monday night in Edinburgh.

Curiosity and openness is a facet of Murray’s character, who, now 67, is the antithesis of the celebrity who avoids eye contact and shuffles past with a minder. And as he tells the story of how he met Vogler, 54, you can imagine him sizing up the other passengers and their bags. He’s clubbable, interested in people, and as if to underscore that point, he has Vogler there with him on the phone from London as the pair talk about

New Worlds. The cello, is presumably stashed somewhere safe for the moment.

“For Jan it’s like a child – you have to think about it, protect it, carry it gently and give it all the love you can. It’s like having a miracle child on the stage, sort of like when those Jacksons realised that Michael could really sing, let’s push this thing out in front!”

What’s Murray’s equivalent, the most precious object in his life?

“It’s funny,” he says, “I hate to sound like a corny guy, but there’s no thing in my life I’m not so scared to break… but I have some sons, you know, those are my favourite things. But I don’t travel with them from venue to venue!” Twice married and divorced Murray has six sons, Homer and Luke with his first wife, and Jackson, Cal, Cooper and Lincoln with his second.

Interviewing two people at once always reveals the dynamics of their relationship and Murray and Vogler complement each other in conversation, easy in each others’ company, inviting the other to answer, deferring to the other’s expertise when we talk about their show: Bill Murray, Jan Vogler and Friends: New Worlds. Murray speaks about the performance of the words, Vogler the music. Murray is all-american, ‘Oh boy! Oh man! Goll-leee!,’ while Vogler’s German accented English is correct and precise.

Vogler explains how the artists the pair have chosen build bridges across the Atlantic, and why they chose the music and literature they did.

“There’s a positive attitude in America, every day it’s a new day and I think that came from the settlers, who had to fight so many obstacles. I like that spirit!

“And I was always a big fan of transatlantic life and connections because Germany was so much influenced by America after the Second World War. America liberated a big part of Germany from fascism so that made a big impression on me as a child. And also, many of my musical ancestors immigrated to America because they were Jewish or had to flee because their artwork was too progressive, so when I came to America I was fascinated to find Europe in America, in the intellectual life.

“The bridge is real. Gershwin was a Jewish composer who composed a piece about a black couple in America in the 1930s [Porgy and Bess] and Bernstein comes to America and composes the most successful Broadway piece ever, about Puerto Ricans in New York [West Side Story]. Ravel composed his violin sonatas after hearing the jazz and blues in the US and Hemingway wrote about Paris. It’s an immigrant country and I feel an immigrant there.”

For his part, Murray says his roots are Irish, according to his parents, but he’s happy to think there’s a Scottish link too.

“Every Scots Murray says I’m Scottish, so I claim all the Murrays.