Sean Ono Lennon , son of John Lennon and Yoko Ono , is very busy right now. When he pops up late to our scheduled Friday afternoon Zoom call, the first thing he does is apologise. “Sorry this was all a bit last minute. I had to squeeze you in because I have an album coming out with my band The Delirium – and I’ve been doing a lot of stuff to finish it off.” Add to that a feature documentary premiering at Tribeca Film Festival, tour dates scheduled throughout May and June, as well as his dad’s special Record Store Day ‘Love Meditation Mixes’ vinyl (which he’s produced) and we’re surprised the prolific, curtain-fringed musician turned up today at all. He’s eager to chat about yet another of his projects though. It’s the upcoming concert film Power To The People: John & Yoko Live In NYC , in which footage of his parents’ famous 1972 charity gigs at Madison Square Garden has been exquisitely restored to crystal clear quality. Seriously, you can make out every single follicle of those iconic sideburns.…