There's a moment on Rush's new R40 Live DVD where you see Peter Dinklage - best known for his portrayal of Tyrion Lannister in HBO series Game Of Thrones - rap over the title track of the band's 14th album Roll The Bones.
Singer/bassist Geddy Lee explains how the star of the hit fantasy television show ended up spittin' rhymes with Canada's most revered progressive rock icons...
"So what happened was Peter's brother, Jonathan Dinklage, was one of our violinists on the Clockwork Angels tour," says Lee, pouring a cup of coffee in his opulent London hotel.
"We had an eight-string ensemble on stage at points and ended up getting close to Jonny, who plays violin on a version of Losing It on this new live release. As it turns out, both him and Peter grew up as big Rush fans in New Jersey.
"So, when we played New York on that tour, Peter came out to the show and cheered his brother on. He's a great guy, so when we were putting this thing together, we asked Jonny if Pete would be up for getting involved in this crazy Roll The Bones rap idea. And he was totally game for it!"
Well, that explains that then. And though it's not the only unlikely collaboration this time round - the cover shot for the release was taken by American baseball veteran Randy Johnson - the most remarkable aspect of R40 Live remains very much in the band's passion for teleporting audiences far into the great beyond.
It's the combined experience of their music and visuals that have made them the arena-conquering rock gods that stand before us today, and R40 Live is the release that, above all others, truly captures their lust for sci-fi escapism.
"I'm always impressed by bands that have more than just music," says Lee. "I remember seeing Jethro Tull back in the day; they were fantastic musicians playing complex things but with great showmanship. They had a great sense of humour that came across in their live shows.
"Pink Floyd were also the total package: always a big show with great music. Yes were like that, too, not so much on the sense of humour front, but a lot of great playing and extravagant visuals.
"I'm also a big fan of the theatre and art installations, which I find really inspiring for things I can use in a rock show.
"A few years ago I was in Kyoto, Japan during a time of year they call Sakura - when the cherry blossoms in April. Kyoto is the spiritual home of the geisha and they celebrate with a theatrical extravaganza.
"There was one moment that was so gorgeous, with multi-layered painted sceneries of waves in an ocean behind people in costume singing. It was so impressive, I explained it to our animators and set designers. And we kinda simulated it for our song The Wreckers!"
Recorded over two sold-out nights in their hometown of Toronto this summer, the footage documents Rush taking us through four decades of mind-boggling musicianship against highly ambitious animations and backdrops. Lee recalls two performances that were unforgettable for completely different reasons...
"It felt like there was a great sense of pride in the house. The first night there were a couple of technical things bugging us and it took us a while to get a groove on, but then on the second we went out all guns blazing and it was one of the best shows of the tour.
"We were happy to have nailed it while the cameras were rolling - you don't always get that when making a DVD. Best-laid plans and all...
"Though we're at a point in our career where we know we can do a good show under any circumstances, to push it to that top percentile where you're locked in and almost reading each other's minds? That only happens about three or four times on any given tour.
"The second night we recorded was definitely one of them! There was a buzz from the fans: we could tell they were appreciating it because there may not be another shot!"
The frontman definitely isn't teasing - recent comments by drummer Neil Peart, who the band revealed had been suffering from chronic tendinitis, had suggested he was contemplating retirement and their touring days were over.
But seriously, what are the chances of UK fans getting one last taste of their time-travelling lysergic blues?
"I really don't know at this point," admits Lee. "We're not sure how many tours, if any, are left in us. Our touring life might be over; it just depends on being able to get a consensus to do more.
"Right now, we don't have a consensus to go out on tour. And unless somebody changes their mind, it's not looking good for that! But I remain optimistic that, maybe after some time, we can twist everyone's arms and get back to work!"
Whatever fate has in store for them, it would be difficult to argue they haven't had a good innings. Lee, Peart and guitarist Alex Lifeson have simply persevered through the decades - outlasting trends, cycles and pretty much everything around them.
There have been no splits, no distracting side-projects, no drama at all - as Lee says, "Not many bands have kept the same line-up for 40 years - it's down to mutual respect, friendship, as well as a united musical vision."
With the prospect of more downtime on his hands, how likely is it we'll be seeing a follow-up to My Favourite Headache - Geddy Lee's debut solo release at the turn of the millennium - any time soon?
"Yeah, sure, that could happen," he nods. "But I have nothing written yet. I'm not the kind of person that has things lying around. If I'm going to do a project, I write for that project. We'll just have to see..."
Rush's R40 Live is available now on Blu-ray and DVD via Universal.