Of course, Young has a lengthy history of political engagement, stretching back to “Ohio”, Farm Aid or, more recently, the environmental project Greendale and his outcry against George W Bush’s military policies on Living With War. This January’s Honor The Treaties shows in Canada were yet more explicit evidence of Young’s political agenda; this time in robust defence of the indigenous First People’s land rights, which are under threat from the Keystone XL pipeline project. In some ways, Honor The Treaties mirrored the 2010 Gulf Coast tour, in aid of residents affected by the Deepwater Horizon oil spill. Oil companies, once again, were the target of Young’s ire. “I think he’s always been an activist as far as trying to do good things for the earth,” says Rick Rosas. “He had been working on this electric car for years and that has something to do with not using fuel. So that’s always been on his mind; finding other ways to use the earth’s energy.”

Sampedro sees Young’s activism in 2014 as part of an ongoing history of protest stretching back many decades. “I think it still comes from his heart,” he says. “If you can make things better, why don’t you?”

Even the seemingly arbitrary appearance of a Director’s Cut of Human Highway at the Toronto Film Festival in September chimed with Young’s current thinking. Originally conceived during a period of protest against the growing use of nuclear power, it’s not hard to see Young drawing parallels between that battle and his current struggle against oil companies.

Willie Nelson’s son Lukas has known Young most of his life. One of his earliest memories is approaching the man he called “Uncle Neil” with a song he had written. “I wanted to show Neil the song,” he explains. “So I had my brother come sing it with me, and we played it for Neil, and he said, ‘Oh man! That’s some good guitar picking.’ So it was cool. I must’ve been 10 or 11.”

More recently, Nelson found himself sharing a stage with Young during Harvest The Hope, a benefit in September to raise funds for the fight against the Keystone pipeline. “We didn’t know what we were gonna do,” Nelson admits. “I talked to Neil briefly at Farm Aid, a fortnight before. He said, ‘You know what I’ll do, I’ll just bring my electric guitar over to the protest. I’ll come and sit in with your band, and we’ll jam a little bit.’ I said, ‘Alright, that sounds great.’ So, we were expecting Neil to come sit in with us. Then when we got there it became us backing both dad and Neil, because we were the ones with the instruments. So we went into Neil’s bus that afternoon, we practiced a little bit. We didn’t have any guitars or anything, he just went and showed us the chords to a bunch of these songs, five songs.”

Nelson shared another spontaneous and hairy experience at this year’s Bridge School benefit on October 25 and 26. “We just went up there to hang, and we were like, well, maybe we should bring our instruments. We figured, if he didn’t have another band, then he might wanna play with us. He did. So we got together, we rehearsed for about half an hour on his bus…

“Neil’s always got so much going on,” observes Nelson. “Even if he looks like he’s just standing there, his mind is working. To us, he’s like Yoda, or something. Dad’s like that too. Those guys, it’s in their make-up. I have no doubt Neil’s gonna be rocking for a long time. Dad’s 81 and he’s still going. They’re cut from the same cloth, and Neil admires my dad for that very reason, too.”